I think it was mostly personal preference, and also like Drac9 says (Persephone's vacuum...HA!). A particular complaint I remember about Pit (and Fox/Falco) was that they had the bow/laser attacks, enabling them to attack from across the screen, which is cheap.
The irony of this is they used characters such as Fox, Falco, and Link, who all had long range attacks. Whether we were attempting to play by their strictest rules (only "A" button, thereby removing the ranged attacks I think), or simply playing in an open arena with no items (any attack was allowed), they always complained about these "cheap" ranged attacks. Sure, you could shoot "one" laser, but then it's as if you were "supposed to" get into the fray and melee it out...and sometimes even that one shot would result in a call of "foul play" or "being a cheap-shot". I eventually got to the point of just doing whatever I wanted, whenever I wanted, with whoever I wanted...and mocking their cries.
Sometimes, if I felt particularly annoyed, I would start being deliberately cheap to counter-aggravate them!
Which, honestly, was just based on their "rules". I think I said that I don't really think there is such a thing as being cheap. I mean, if you want to use someone like Fox, spend the time running away or dodging me while spamming the laser, that's fine, go for it! It's then my job to figure out how to counter that and beat you, not cry about it. If I can't...well, it may be annoying, but it's still an effective strategy.