But not all military codenames are for operational security and therefore changed regularly...that was my point.
Exactly. There is real-world precedent for using code names, so it's not just some goofy comic-book thing. So the way so many superhero shows and movies act embarrassed about the code names and try to avoid using them is just unreasonable. At the very least, it'd make sense to use the code names in action and civilian names the rest of the time. Arrow actually has adopted that practice in the past season. Age of Ultron may have as well, at least in the opening sequence, but I don't recall whether that was actually the case or just what I was thinking should be the case.
As far as superheroes who change their code names frequently, there's not just Hank Pym, but also Kitty Pryde, Carol Danvers, Monica Rambeau, and others.