Most of these sort of books are meant for beginner writers, that's why. There are some amazing writing books out there, but the big popular ones are the easily digestible beginner ones. Personally, I love Sol Stein's Stein On Writing that gives a more down to earth, helpful realistic look at writing. Just like the most popular writing advice youtube channels are often just lists of the same basic tropes and advice over and over in 20 minute chunks because they're for beginners vs the channels that do several parts for up to an hour at a time going in depth.And just like how the most popular art books art "how to draw" and go over the same basic lessons over and over in different fonts.
This is conflating 2 different issues. You absolutely should write what you think is good. No, not everyone will like your work and, yes, people do have different tastes. None of this is wrong. There's a perfectly good point here about taking criticism and not letting the idea of people having different tastes stopping you improving but that "inspirational bs" is actually good advice that is objectively true.
You know GL is a type of Romance right? If you tag it GL it's romance. Wow, people read a romance and were interested in the romance? Here's some non-sugar coated advice, even taking from your own earlier advice about making excuses: don't blame your readers. Maybe your GL romance was just the most engaging part of your story. Or maybe you tagged the wrong genre. While it's perfectly valid to say you want one part stronger than the other, if all your audience is talking about is the minor part, you've either tagged the wrong genre or your writing is weak in that area. And dropping it because is pretty petty, to be honest. As a reader, I'd be wary of reading works from an author who just drops works like that.
Also, while it fine to say you don't tag these things, they're important tags. Because they help people find books they're interested in. Maybe lesbians want to find GL. Maybe trans people want to find stories about trans people. And maybe some assholes will throw a tantrum and spam you if they expected a het romance and got a gay one.
Not to mention bad representation is not the same as forced. Maybe rookie writers aren't forcing it, maybe they want to write a romance that's includes these things because they want to. Maybe it's unnatural because they're rookies and don't have a grasp on writing yet, let alone good romance. And why just LGBT? You just gonna ignore all the veteran writers who write unnatural, god awful, forced straight romance? This isn't an LGBT thing, or a rookie thing, this is a writing in general thing where some time people just suck at writing romance.
Sorry if a lot of this seems harsh, but while this advice seems like it's coming from the right place, the not sugar-coating just makes it come off as rude in places and almost like you're trying to be edgy and undermining your own point in others. Not to mention, doesn't seem like it's taking Tapas' specific market into account, especially with the LGBT points, where this is a big plus. You seem to be playing cynicism and negativity as honesty a little.