The biggest problem with the BW tournaments is that they adhere to a predictable writing formula that doesn't work. Come the World Tournament, we all knew exactly what we'd be getting, even the rival interactions which are the saving grace of the tournaments are really quite stereotyped and repetitive. It's like the writers have all these great characters, but can't think of anything better to do with them.
Extremely rushed battles don't help either, but that isn't exactly an issue exclusive to tournaments.