Unlike many (most?) others, I don't hate The Crystal Star -- I actually found it a fun read the one time I read it.
I admit, though, that my perception is coloured by my love for parallel universe stories. Perhaps if there were more and better Star Wars stories which dealt with parallel universes and divergent timelines, I'd be less forgiving of the book's flaws. As it is, though, I have to accept what little's been given to me.