User blog comment:OnePieceNation/Which of these series wouldn't you mind getting a crossover with Hunter X Hunter/@comment-9096809-20130701204533/@comment-4783583-20130701205201

1 that they are filler is fact, that they aren't good is a matter of opinion.

2 some are short others last 2 hours.

3 once in a while they are made to promote a new series but not all the time, more are made to celebrate an annivisary of a series.

4 the anime writing team rarely brings in outside writers just to write a crossover.