I think it's not really hated per se, so much as just very few people have gotten to watch it (in part due to a lack of subs, maybe the guys doing Amazon will pick it up next?), and even in Japan it's often overlooked, coming between a powerhouse like V3 and genre-busting Amazon. Just following V3 is a task I don't envy. New Kamen Rider (or Skyrider to the uninitiated) is the other one everybody forgets about, and both of 'em are some of my favorite Tokusatsu shows ever. There's probably a story to that...
I'm kinda hoping that the next couple of Decade episodes might encourage some people to give some of the older stuff a shot (and conversely, the older fans who tune in just for Kurata,etc. might see the new Riders aren't the work of Satan. I wish I were making that up, but it's pretty close to a real quote I once read about Ryuki. Oh, you crazy fandom.) Though I dunno, has Decade gotten anyone interested in going back to watch Kuuga, etc.?