It's not hate, it's common sense.

Why do some people (especially online) consider anyone questioning or speaking out against topics which are possibly sensitive or trending at present automatically assume you're hateful?

Hate is such a strong word and thrown around so much. Noone should be labelled hateful or anything for showing genuine concern for minors or voicing an opinion.

Those resorting to insults because not everyone agrees with them evidently feel threatened, are questioning themselves or simply aren't mature enough to discuss the topics in hand.