I had the luck of two exceptional stat arrays (3x16s) and one quite bad one (maximum stat: 1x14, lowest stat 10).
I actually were allowed to reroll my bad array and rolled another exceptional array. But I decided to take the low one and optimized the fun of that character.
In the two exceptional cases I decided to play a fighter and a melee wizard, two classes that don't scale too much with above average stats. So if you have a social contract that allows high and low array characters to play at the same table, and allow the choice to reject a low stat then there should never be a problem.
If of course, all you care is combat performance and there is no appropriate social contract, then rolling is a bad idea.
I'm happy for you if you want to play a PC that can't (by the numbers) contribute equally to the team. It should be a personal choice. I'm just giving my preference.
I don't see a reason to roll for ability scores other than to assure inequitable results.
