As with many music genres, film franchises etc etc IMO the hatred/dislike targeted at prog is probably less to do with the bands music rather than their, often rabid, fanbases. When groups of fanboys declare Rush/Tool etc are the greatest band ever and knock spots of everyone else that's what puts other people's backs up. It's fanboys on fora who keep harping on about things like these bands supreme technical prowess, use of complex time signatures blah blah. Diehard metalheads seem as bad.