Steam keeps recommending me roguelikes no matter how many of them I mark as "not interested" (you'd think that Valve would figure it out by now).

Roguelikes are crap for several reasons:
-There's no real content. They're just grinding to level up and gear up.
-No save file management, actually most roguelikes delete your character if it dies.
-Highly RNG dependent - you could get screwed over with bad gear or unreasonable enemy combinations.

It looks like a lot of indie developers want to write games with no story, no real content, just grinding and more grinding.

Not really. It's a genre I find quite enjoyable, with some of my favorites including The Binding of Isaac, Risk of Rain, and especially FTL. One reason I find them fun is simply the replay value behind them. With the RNG is every run always going to be different, be they good or bad. Discovering all different kinds of items and buffs that grant fun abilities and its nice to see how they can mix in with some of the classes that roguelikes most of the time have in their games. Not to mention some roguelikes like FTL actually require a lot of strategy.

As for saying they have "no real content". I don't know how you came to that conclusion. There is an immense amount of content in roguelikes like The Binding of Isaac: Rebirth. I remember killing the supposed "final" boss of the game, only for there to be tons of more content that unlocks afterwards. New bosses to fight, new areas, new items and abilities to be found. Both in previous dungeons and all new dungeons. The game has a load of content in it.

As for no save file management, well, permanent death is where a lot of the fun is found in roguelikes. They're all based on going through different runs and seeing how far one can go before meeting their ultimate demise, or enduring it all and finally coming out on top. It's just part of the challenge and intensity of it.

Perhaps its a genre that just isn't for you (unsurprisingly, of course). Because we all have different taste.

I agree there's a lot of trash on Steam. But like survival crafting games, it's just the result of people trying to cash in on what's popular. And Greenlight helps keep the trash pile fairly high.

There are some excellent games, and FTL is certainly one of my favorite games in large part because of how the RNG makes it a new experience each time.

Not really, because I don't pay them any attention or play them.

Been playing "roguelikes" in various forms since Rogue back in the.... 90s? (Rogue/Moria/Angband/etc, Diablo/Torchlight/Titanquest & all the other ARPGs, FTL.....)

Are there a lot of them popping up right now (as well as stretching the definition of roguelike/roguelite)? Absolutely.

But....

And if you think about it, your problem isn't necessarily with roguelikes, it's with Steam's recommendation system.

Just got into roguelikes this year. I like quite a few of them for their tabletop feel and retro b-movie music flavor. Some of my favorites are:

The Darkest Dungeon

Dark Quest

Warhammer Quest

not really.. if I see a game on steam i don't have interest in, I just ignore it and look at the next.. being obsessive about products that show up you have no interest in is sorta childish in my mind (especially since most recommendations steam makes are based off games you frequently play)..
your going to see a lot of products, people, and concepts in life you really won't like, don't obsess over "but i don't like this", and instead just ignore and brush past it till you get something you do like

I don't know. I absolutely love FTL and Spelunky. They're just so imaginative and challenging. You can tell when a game is a dud, and those two are certainly not duds.