How do you expect to see change when people aren't showing support for the content? These companies are clearly trying to diversify their lines and people are vocal in wanting it, but don't want to buy crap. You say the system is rigged, but that's just means you need to take advantage of the opportunities you do get. For example, you say that people have wanted an America book for years, but if they don't support it then it's obviously not going to last and the same people will come back to complain.
Also, Brevoort said the myths about only certain types of sales mattering is BS.
A) If money is the only thing that'll make Marvel do the right thing, that's very much fucked up, and, considering how big of a deal they make about being super cool and progressive, it feels super hypocritical
B) Especially considering how little effort they put into making and marketing books with diverse characters. Like, for every Ms. Marvel, which, let's be honest, is One Ms. Marvel, there's at least 2 or 3 Red Wolf
C) Yeah, remember Red Wolf? That was a thing! That was practically sent to die, and which got cancelled faster than checking who was on this book that was not Nathan Edmondson
These are choices that Marvel are making. And, as long as they make them, things aren't gonna change.