The thing is, there's this guy at a manga site that I always frequent (you probably know who he is if you went to mangapark long enough). He just LOVES dissing on these supposedly self-insert isekai harem stories. He would find one, gives it half a star, then copy paste the same crappy review of "OP MC getting a harem, blah blah blah". He's the very reason I asked the question onthe post.
Before I became a writer, all I thought then I saw his "reviews" is that "man, he must be very bored". After I became a writer myself, however, I started to hate on guys like him who just starts crapping on others' hard work without giving a proper criticism.
Well, yeah. People like that exist. If you're trying to create something, 'reviews' along those lines dismissing your work will always pop up. We don't need to go into or guess why, but they're there. And they'll always be there.
I get the point you're making about how it's anger-inducing seeing people be so dismissive and how it can seriously cut down new writers or creators. But the fact is that if you aren't willing to continue creating the thing that only you can see when others try to snuff out your vision and blind you with their words, you probably shouldn't do it. Or at least, you shouldn't reveal your effort to the public until it's complete. Though that comes with its own host of issues.
This is especially true for self-insert stories, whether that self-insert is intentional or not. That character is 'you'. And the story is 'yours'. While that's true in an abstract sense for all stories, it's concrete for a self-insert story. And because of that, it's even more important to remember that the ultimate decision maker at the end of the day regarding the story is you.
Going back to your initial post though, no sort of story is 'wrong'. If it's a story you want to tell, and if it's a story you've told, it exists. And the mere act of existing isn't wrong, no matter how many people these days might argue otherwise. And inserting yourself into your stories, whether in part, implicitly, or explicitly (in every sense of the word) isn't a bad thing. In fact, if you do it sincerely and with enough passion, you'll likely find people who respect or even enjoy your work.
Though, you have to keep in mind who you're writing for. If you're writing for a certain type of reader, then you have to mentally remember that they have the final say on what is good or bad. Going stubbornly ahead without remembering that will only lead to disappointment all around.
As to the "same crappy review of "OP MC getting a harem, blah blah blah"... Just remember that for every extremely dismissive and hateful comment, there's at least one on the opposite extreme. There are a few people who
hate OP MCs and harems with enough vitriol and energy that they could fuel the entire world ten times over for years if we could harvest that. Nothing you say to them will make a difference since they've already created a mental shortcircuit whenever those keywords come up.
Think of them kind of like self-programmed bots with an 'if these tropes, then flame and hate' loop.
On the other hand, there are also people who go 'if these tropes, the five star and like'.
People are people. At the end of the day, what matters is whether you're willing to tell the story you want to tell, in the way you want it told, to the people you want to tell it to. If not, then just stop. People might judge you, but at the end of it all, you're going to be the harshest judge anyway, so who cares what others think?
-This essay is brought to you by your local Happy Vainglory.