Insult and abuse hits harder than reassurance. If you were in a situation where you were accepted and sometimes celebrated by part of society, but the other half of the people you were around were hateful and mean, that is difficult to live with even if there are people on your side. It takes a toll on some people, knowing that much of the world hates them for who they are, and that some even probably want them dead. This, and also how they are often socially isolated, is why suicide rates are so high for LGBTQIA+ people. Finally, I am not sure that 'constructive criticism' can help with this, because this truly is not an issue that they have brought upon themselves, but it is a broader issue that is rooted within our society.