I apologize for the fact that I honestly have no context whatsoever to make this fic make sense to me given that I don't know the fandom it's being crossed over with at all. But I understand the desire for constructive feedback and not getting any at all. Just wanted to say that I think that as tempting as it is that it doesn't generally help to insist that people give you feedback when they're not doing it anyway, whether the fault is yours or theirs. Writing only gets better with two things at its center: 1) more reading of writing you find good that others at least somewhat agree is good and 2) practice that is mindful of what you are practicing. It is not just cranking up the volume of what you are producing and writing more words blindly. It is looking at something that is not your own, deciding what you think is good about it, and analyzing why it is good. It is also looking back at criticism of your other work that has content to the criticism rather than just insult and figuring out how you could respond to that in a positive way. Also, if you are actually paying attention to your own process while you're writing, rather than just writing out more of the same, that is how practice makes you better. This is not actually good criticism of your work, because as I have mentioned I don't have a good enough background to feel like I can read, understand, and critique it. It's just general advice.
That said, could we like, as a community, not tell people that what they're doing is a waste of their time if they're actually trying to improve? There is a difference in constructive criticism and heckling. If we find something genuinely hopeless, let's just... not tear down people's self image in the process.
But on the flipside of that, don't as writers be so egotistical that "this isn't working," just always means that you are going to make people see that it works. There's a balance, but just... don't be mean to people?