It actually might be because you won't gain TP as fast. There hasn't been enough testing to conclude anything about low delay weapons compared to high delay weapons. TP doesn't seem to be based on delay either.
When it comes down to it there hasn't been enough testing to conclude anything. It kind of reminds me of FFXI when it was believed that slow strong hits were the best, but then haste gear became more readily available then the meta had changed.