Again, who are they? What are they saying that you feel is bitching? You saw one guy who voiced a single text line of an opinion of a general theme in a very broad medium. You are saying things like "These kinds of people", "Special snowfalkes" and "They only care." (twice in a row mind you) You are making all these claims about someone who literally said three sentences. One of which was four words long.
Even if everything stated before was not true the things you brought up: >Dislikes the main heroine>Likes to root for the underdog >Liking unpredictability
These are all opinions. People like things for different reasons, and that is fine. People also get different experiences out of the same thing. You might read a book and laugh. I might read the same book and cry. There are THOUSANDS of types of romance literature and visual media all directed to different audiences. All that happened was someone voiced a very VERY tiny opinion about a topic in hopes for discussion or to find someone who thinks similarly and you immediately shut them down and made all sorts of claims to the person he is.
It's like>I don't like mustard on my sandwiches. >"Your taste is shit objectively and you don't know enjoy a sandwich."
That was that interaction. I am just saying it sounds like a snap reaction to defend a waifu without actually saying "don't talk shit about my waifu."