I personally don't care if they revamp an old character, or make new ones. Considering how often heroic figures are just modern reskinnings of classic archetypes and the like, it's not that big of a deal to me.
Given the Peter Parker example, I don't really have any vested interest in him being a white, heterosexual male. It doesn't matter to me, and it doesn't actually impact the story at all. Aside from the occasional "we're going to talk about racism" issue that they like to do in comics, for the most part, his race/gender has zero impact on the story. And given how generically Everyman (or at least as Everyman for a white guy) he is, his personal identity is kind of unremarkable. There's nothing intrinsically "white" about who Peter Parker is. I've discussed this before in similar threads, but his defining personality traits (things I find more important than his gender/race/orientation) are:
Nerdy
Awkward
Courageous
New Yorker
Hero of the People.
All of those can easily be attributed to any other New Yorker, of any gender/race/orientation.
So personally, I don't care if they shake things up, after 60+ years of the same Peter Parker (or any other character). I didn't mind the concept of Female Thor, though I personally didn't like the way they went with the writing of it.
I loved what they did with Miles Morales, and genuinely enjoyed his heroic arc. And I know you (and I) don't care if it's a "Legacy story" kind of thing, like with Miles, but a lot of people do, as evidenced by the uproar a lot of these changes have made.
I dunno, I guess I just don't have that much personally invested in the hero looking and fucking the same as they did when first created. If someone wants to make a gay Peter Parker, who also happens to be transgender, and of mixed ethnicity, go ahead. I sure don't care about the concept. If they just use the platform to write terrible cliches of those ideas, then yeah I'll have an issue with it, on the "this writing sucks" platform, not the "They've done a character assassination of my hero!" platform.
The heroes change with the culture they are written in. This is true of the heroes we love now, compared to how they were when they were first created. This isn't new ground.
Also, on the flip side of this, form the "original IP" angle, which I agree, more of those would be good too.
I think it's kind of strange, how I suspect a lot of people, if they did make some new IP, and made them trans, or non-white, or non-hetero, or whatever, I suspect a lot of people would be "oh, that's just that Gay Hero they made" or "that trans hero", and write them off because of that. And that won't help get the character into the spotlight, which is where they need to be to sell enough comics to be profitable. If the character is always a niche character, it would likely die off, simply due to not enough people buying the comic to make it profitable. So it's sort of a catch 22 I think...or maybe that's not the write comparison. I dunno, it's weird, I don't see an easy way of having it work. Because those established names have selling power, they have momentum in the comic world. Trying to muscle in on that block is hard, and maybe too hard for a new title to actually make enough headway to sustain itself. So then, if that's the case, you then have to try new variations on the established heroes, if you want to try different stories.
Most people have a limited entertainment budget, and if they are faced with the choice of buying a title they know has a history of telling a decent story, and taking a chance on some unknown title that may/may not suck, a lot of people will choose the safe option there. Which would negatively impact sales of the new IP, which at the end of the day, is the bottom line. We can talk about the art of it, and the expression of stories and all that, but it's still a business, a very niche business in itself. So to step away from the proven titles that move issues, and try and make a niche market, within a niche market, and hope it's profitable? I think that given the current business model, that might be too big of a feat for any new IP to accomplish. I'd like to think they could, but I have my doubts.