To begin, if the pick/ ban system stays exclusive to the ranked mode, I’d consider it mostly harmless and about 90% of the player base won’t care.
As far as people crying and quitting because they don’t get their favorite character, or the other team has a certain character, let them. F**ck them, what are they, ten? They shouldn’t be playing competitively anyway.
See, because Battleborn’s big secret is that it’s an FPS. There’s three dimensions of movement, and there’s a way to get around every character’s abilities. Any character can kill at least twenty of the other characters, and any random number advantage can be countered by shooting them in the face.
An actual competitive team should have a plan, a start, and a contingency for every character. Be polite, be courteous, have a plan to kill everyone you meet. Apart from the occasional runaway like Ambra or something, bans should be entirely uneeded.