My parents didn't necessarily hate it, but they had/have zero interest in it. It's one of the reasons why our relationship was a bit rocky. They just never got it and never tried to really get why I enjoyed it so much.
The bigger issue was my brother. My brother was beyond not trying to understand and I assume he hates it. I don't know why really. It has caused tension between us. At one point, before my husband and I were married, we were chilling at my parents' house and decided to watch a couple episodes of the anime we were currently watching - Vision of Escaflowne. I don't remember exactly what happened... I think my parents and brother were talking really loudly (we're a loud family) so we turned up the volume a little.
My brother came charging into the room pissed off and yelling. My husband is a completely chill guy and said something non-confrontational, like "We're just trying to watch the show" and my brother went right up to HIS FACE and started YELLING at him and threatening to fight him. It was a really awful moment.
Thankfully, my brother has calmed down since then.
There was a time when my Dad and I were waiting for my mom or something so I threw on an episode of an anime I thought he might enjoy, which was There's a Corpse Buried Under Sakurako's Feet (I think that's the name). He did seem to enjoy that at least.
I dunno... my parents are weird. They're pretty not adventurous in what they watch. Usually game shows or Seinfeld or sports and my mom will watch the western type shows, though she has gotten into Game of Thrones and is excited for the final season.