I think its mostly because of how often its used in the wrong formats & contexts. There have been professional advertisements that went terribly wrong simply because of the font. Professional businesses frown upon Comic Sans (and Times New Roman as revealed in a study). And certain games get people riled up & up in arms over Comic Sans. It could also be the general look of the font itself, which doesn't exactly shout professional or even clean. I could be wrong, but I don't think comic sans was ever meant to be used outside of... well, comics.

But this is 2018. People probably hate on it now a days because hatred is a very "hip & trendy" thing to wallow in among the "average" internet user. Just like how people hate on, say, No Man's Sky, or Ubisoft, or Cuphead, or furries, or even millennials as a whole. (as much as people won't admit it).

I see interserting