I think for some people everything is sexual and so for them if you like anime you must be into kids, non stop masturbate or something like that.
And truthfully they have reason to think like this because well rule34 servers are full. The art itself is inherently, well Japanese are weirdos after all with some troubled ideas.
I am constantly at odds with anime. I like it in its best form but absolutely despise it at its worst. You can't really hate whole anime anyway it doesn't make sene. Some anime is cool and fun, some is absolutely degenerated view on a horrible mind of an author.