Also, do people really get "enraged" about less popular pairings being written?
Yes.
Not in HP or Naruto fandoms either. Seen it in plenty others.
Basically anything that goes against a fanbrat's OTP is cause for intense hatred and much frothing at the mouth. The saddest thing I've encountered the worst of it from slash fans, which has pretty much soured a lot of my enjoyment on the pairings I do like.