I always knew they were sub par, but when they were put on a pedestal by Lucas who can release them but not the OOT, it made me hate them. I also started to hate them because they made the EU a big chunk of utter crap. And they turned the fan base into a bunch of Yoda quoting nerds.
I was a Star Wars nerd in the 90's, but the PT made me identify myself as a fan of the original originals. You really have to love them all to be classified as a Star Wars nerd nowadays.
I also realized I wasn't a Star Wars nerd anymore, when conversations with Star Wars nerds became a frustrating argument. I can't sit with today's Star Wars nerds and be one myself. The last time I did, they sounded like that bald guy in the People Vs George Lucas trailer "Mr. George Lucas, we the fans (the TRUE fans), salute you!!!"
I can hang out with you guys all day, because you have seen the good ones in their original glory.
Another instance of me hating the PT, was when I started making DVD covers. Try finding good images of the OT without having to go through pages of prequel crap.