[incompatible]

Uncomfortable ideas, for vulnerable people, I guess would be the kinds of ideas that make them vulnerable in the first place. E.g., that same-sex relationships are against God or against the natural order of things, or that women should naturally be subservient to men, or only have themselves to blame for sexual violence. I've heard that there are forums on the Internet where such ideas are explored freely.

Edit: A forum that bans discussions like that, will probably be seen as left-leaning by some.

[sacrosancty]

That's just obscure political correctness. I'd say it's far more often people who lack emotional maturity or self confidence and have any of all sorts of common insecurities that they don't want to be reminded of. Imagine being called an idiot when you actually have a low IQ? It hurts and it's far more common than being gay in Pakistan or whatever.