William Shatner’s Comedy Central Roast was so good because it gave stars the chance to express pent-up rage they’ve had for years at this alleged Hollywood grouch. It turns out that while on the set of Star Trek, most of his co-stars hated him because he behaved too badly towards all of them He garnered the name “Captain Jerk” for not showing up to Leonard Nimoy’s funeral. It's not the most creative mean nickname, but it definitely gets its point across.
While at conventions, he has a huge attitude that fans and co-stars are forced to put up with. At one point, he shouted at Denise Crosby (Tasha Yar from Star Trek) any time she tried to answer a question. After seeing the way he acts toward his co-stars, it's impossible to have respect for the man. And as far as upsetting fans goes, he might not have to worry about that much longer because his bad behavior seems to be driving away any fans brave enough to stick around.