I answered Point Buy (custom) because I use a mod total system for my D&D games. I think it would be absurd to put all this work into "balancing" classes, abilities, encounters, etc. and then have one player's stats be better than all the others. Particularly given that my players never used to deal well with those sorts of inequality.
However, in different style games (CoC, focused more on story and character and not requiring mechanical balance) I have stats rolled (and rerolled if we don't like 'em).