When Hank Pym created Ultron, he was just treated as a human making mistakes. But when Tony Stark created Ultron, he was treated as a monster, manipulative, narcissistic, evil and less than human.

Tony Stark is a billionaire genius with a whole arsenal of weapons at his disposal. For him to maintain a secret identity is something that can be easily manipulated by his enemies, who are very powerful and part of the global elite.

And if heroes can have secret identities, why can't police officers have secret identities? They and their families are also in danger, even more so than superheroes who can defend themselves. Why can superhumans have the privilege of a secret identity, but human police officers can't? What really differentiates a vigilante from a policeman?

They need to promote Sam Wilson as Captain America.

It stands to reason that they'll turn Tony Stark into an authoritarian, one-dimensional, narcissistic villain to do so. 

I like your idea. But Iron Man has always been more corporate/political thriller than spy thriller. I don't know the Laundry Files series by Charles Stross, but I wonder how a crossover between the two could happen?

There's nothing more annoying than comic book nerds who read their comics, go home after work, school, or college (if they actually work or study), and spend their time online posting nonsense, complaining about everything. They feel oppressed for any reason and refuse to accept that there are people who like things they don’t, trying to change what doesn’t please them.

This is exactly what happens to transhumans in Marvel. The only difference is that they are vilified and turned into elitist, narcissistic, billionaire stereotypes who want to control all of humanity, superhumans, mutants, and any living being they encounter. They are seen as a constant threat and have no access to any healthcare system that ensures even a minimal quality of mental health care.