The problem with indie games is that "indie" isn't a genre at all. Indie used to mean independent(as in self published, self financed), but it's been mutilated to mean "pretentious 2d puzzle platformer that purposefully looks bad". I'd definitely disagree that indie games suck, but I wouldn't hold it against you if you thought all "indie" games sucked.
Most indie games don't appeal to old-school gamers, they appeal to posers and hipsters who think they're industry veterans. Many indie games merely take the appearance of looking retro by being ugly and pixelated(which is a ridiculous "art style" and stereotype), but their designs don't reflect old-school games at all.
I don't know if I agree with you completely, not in January 2014. While I do agree that indie is not a genre and shouldn't be seen as such, I think we're at the point in the indie revolution where the stereotype for indie games to look a certain way is outdated, and isn't shared by the majority anymore. In fact, most big names that actually look quite nice, (Astebreed, Spelunky, Giana Sisters). Generic Old-School callbacks are exactly that: Generic Old-School callbacks. Their aesthetic alone isn't enough anymore, and they depend on actually being unique to succeed.
I've mentioned Two Brothers before, and I think that's the perfect example of a game that chooses an art direction and tries to appeal to Old-School gamers while still making an experience that's engaging and truly unique. It's a Gameboy game for the PC. In every way, it feels like a gameboy game, but the art's attention to detail and the game itself don't make it feel like a callback, it makes it feel like a genre-saavy Gameboy game.
But I think one thing to consider is that, with indie games, part of the deal is the drive to execute one's ideas. I think you said it well when you said "A lot of developers have the potential to produce something great, but there's no point in doing something great when people will accept whatever trash is shoveled out from them." With indie games, there are no restrictions, and a lot of people make games simply because they have an idea. Maybe they don't have the talent to execute such an idea to its fullest. Maybe they're not an artist or they can't make the greatest music, but they try their hardest with what they have, and I think that that's respectable. Having the drive to execute what one feels is a great idea despite their insecurities definitely isn't easy, and for that idea to become popular is unreal, but it happens.
I'm not saying that one shouldn't try to make their game that looks good by gaining the skills themselves or building a team of individuals, but I wouldn't say that they're trying to appeal to some sort of "pretentious hipster demographic" by hiding under the guise of a callback and calling it artsy. That may have been the case in the Post-Voxel (aka Post-Minecraft), Post-Braid period of the revolution, but it's barely the case now, for reasons I've stated above. Their aesthetic and "callback concept" aren't enough anymore, indie games become popular because of merit and execution rather than simple on-the-surface concepts alone. I'd say that there are a number of titles that do accurately callback to retro days (and many others that don't).
And yet most mainstream games are STILL superior to indie games. Even with all of those handicaps that you mentioned. What does that say about the indie video game scene? Name one indie game as good as The Last Of Us or Bioshock Infinite please. I'll wait. See you can't think of any, no one can. Because those are the gold standards of our video game industry and no indie video game developers will ever be able to measure up to the big leagues. Even Call of Duty, a franchise that's a shell of its former self is still far more enjoyable to play than most hipster indie games. You get what you pay for.
Takkoman, Touhou Project, The Stanley Parable...and why do keep mentioning Hipsters? Do you even know what hipsters are? Hipsters aren't even a prominent thing anymore, certainly not in the eyes of indie devs. Maybe 3-4 years ago it could possibly...maybe...start to count as some sort of convincing argument, but they just aren't relevant anymore.