Many of the worst villains presented in the Marvel Cinematic Universe shows and movies had plans that were illogical or shortsighted. Sometimes this was because they were so blinded by rage that an easier method of achieving the same ends did not occur to them. More often than not, however, they just did not think things through or fully consider the consequences of their actions once their goal was achieved.
Granting that some degree of melodrama is necessary for the superhero genre to function, there are many occasions in the MCU where the villains' actions only make sense within the context of a written script. Many Iron Man villains, for instance, would have been better served finding ways to market the technology they developed and trying to put Tony Stark out of business, rather than building doomsday devices and trying to kill him. This would be more logical, but also deprive audiences of the epic action sequences now synonymous with Marvel Studios. Still, it cannot be denied there are some MCU villains whose plans made them look terrible and foolish.
12 The Fake Mandarin in Iron Man 3
The Mandarin is Iron Man's greatest enemy in the world of Marvel Comics. Iron Man 3 made a show of introducing the Mandarin as a terrorist leader, but this was all part of a clever twist. "The Mandarin" was ultimately exposed as actor Trevor Slattery, who was hired to play the part of the Mandarin to cover up Aldrich Killian's failed Extremis experiments. Ignoring how the real Mandarin was less than amused and later broke Slattery out of prison to punish him for the insult, it is hard to see how pretending to be a terrorist leader could end well for Slattery,
11 Loki in Thor: The Dark World and Ragnarök
The God of Mischief, Loki, is a chaotic being who will do many things for spite's sake. He succeeded in his ultimate goal of usurping the throne of Asgard at the end of Thor: The Dark World, secretly replacing his adoptive father, Odin. This made it somewhat underwhelming in Thor: Ragnarök, when it was revealed that Loki had allowed the Nine Realms to fall apart. Rather than showing his skill at ruling, as his sibling envy had suggested he would, Loki had seemingly done nothing more with his newfound power than build a statue of himself and commission a troupe of actors to stage a play about how awesome Loki was. Considering how weak Asgard became, Loki effectively put a target on himself by not thinking of the follow-through.
10 Zemo in Captain America: Civil War
Baron Helmut J. Zemo was a survivor of the Battle of Sokovia, who blamed the Avengers for the death of his family. Knowing that he couldn't face them directly, Zemo enacted a complicated plan that would turn the Avengers against one another, framing the Winter Soldier for the death of King T'Chaka of Wakanda. While Zemo's plan was effective in forcing a wedge between the Avengers, it depended on too many random elements he couldn't control. And more pertinently, he could also have accomplished the same end far more easily by simply revealing how the Winter Soldier had killed Tony Stark's parents.
9 Vulture in Spider-Man: Homecoming
Adrian Toomes lost his business after Tony Stark and Damage Control took over all the salvage operations in Manhattan following the Chitauri invasion of Earth in 2012. This pushed Toomes and his employees to turn to crime, studying the Chitauri technology they had scavenged and reverse-engineering it to set themselves up as black market weapons dealers. However, there's no clear reason why Toomes and his team couldn't have done the same thing and pursued legal avenues of selling their weapons. While this was unlikely given Toomes' desire for revenge on Tony Stark, it would have been a far safer way of feathering his nest than becoming the MCU Vulture.
8 Killmonger in Black Panther
The son of an exiled Wakandan prince, Erik "Killmonger" Stevens sought to usurp his cousin T'Challa and use the resources of Wakanda to fight inequality on a global scale. Killmonger was a brilliant strategist and his ultimate goal was irable, even if the means he utilized to become King of Wakanda were not. However, he was remarkably shortsighted in his belief that the people of Wakanda and the rest of the royal family would kowtow to his plans immediately and that no one would oppose his rule once he seized the throne. He was also overconfident in his ability to hold on to what he had taken and ultimately paid the price before the majority of his plan was even able to be realized.
7 Thanos in Avengers: Infinity War
Rather than literally courting the personification of Death, the Thanos of the MCU sought to end intergalactic conflict over resources by reducing the population of the universe to a manageable size. This inspired Thanos' quest for the six Infinity Stones, which would give him the power to alter reality and kill half the people in the universe. Ignoring that this would not address all the reasons various species went to war, it was unclear why Thanos couldn't just use the Infinity Stones to create more resources or do something with his pronominal cosmic powers besides kill people.
6 Mysterio in Spider-Man: Far From Home
Teaming with other disgruntled former employees of Stark Industries, engineer Quentin Beck faked an extradimensional invasion with advanced holograms while posing as a magical superhero called Mysterio. All of this was part of a larger scheme to steal the EDITH glasses entrusted to Peter Parker, giving Beck the power to stage a city-wide battle and become a more famous superhero than Iron Man. However, Beck's technology was impressive enough to fool the world without EDITH, and good enough to get his foot in the door at SHIELD. Had he not been obsessed with toping Tony Stark, Mysterio could actually have been a real illusion-casting superhero.
5 The Flag-Smashers in The Falcon and the Winter Soldier
Formed in the wake of The Blip, the Flag-Smashers were devoted to restoring the sense of unity between nations that briefly governed the Earth following Thanos' destruction of half the life in the universe. This pushed them to steal Super Soldier formula, as they violently worked against the Global Repatriation Council, which they felt was unjustly ignoring the plight of those who were displaced during the Snap. While the Flag-Smashers had a point regarding the GRC's mismanagement of resources and found a sympathetic ear in Captain America Sam Wilson, they would have been far more effective as activists than terrorists, given the impact on public perception they'd need once they took over.
4 Scarlet Witch in Doctor Strange In The Mutliverse of Madness
Following her acquisition of the Darkhold, Wanda Maximoff became obsessed with restoring the family she had lost. This led her to hunt a teenager called America Chavez, who had developed the power to independently travel the multiverse. Wanda schemed to steal America's powers and use them to travel the multiverse, so she could replace the Wanda Maximoff of another Earth and live the life she wanted. Granting that the Darkhold was pushing Wanda to evil ends, it is still surprising it never occurred to her or Dr. Strange that they could just find an Earth where Wanda's children were orphaned and in need of a mother.
3 HulkKing in She-Hulk
A spoiled son of privilege and a total misogynist, Todd Phelps didn't believe there was anything his money couldn't buy. Taking offense at the existence of She-Hulk, Todd formed the on-line troll group Intelligencia and as HulkKing, encouraged his followers to attack and degrade minority superheroes in general, and Jennifer Walters in specific. He also schemed to steal her blood, so that he could copy her powers for himself. Allowing that Todd was an idiot with more money than sense, it is hard to imagine him honestly thinking his wealth would protect him from SHIELD or the Avengers, had he been successful in becoming a Hulk.
