CP3S said:
Bib Fortuna and Jabba the Hutt scoff at the idea of Luke being a Jedi. I guess that could be taken as, "Wow, a Jedi. Haha, what a kook" or a, "Him? A Jedi? Yeah right!", I've always taken it as the first.

Their reaction makes sense because

A) All the Jedi are supposed to be dead.

B) If a Jedi did somehow survive, he would be middle-aged to elderly.

Also, Jabba and Bib are technically correct because Yoda explicitly said Luke would only be a Jedi after defeating Vader. So, if you'll forgive my use of PT jargon, Luke at that point was a Padawan and not a Jedi.