I'm 100% down for having an option to roll too. Aside from it just being tradition, it adds two things IMO:
1) It adds additional difficulty customization. Yes, rolling higher on all stats will make the game slightly easier, and vice versa - it's basically an additional adjustment you can make to difficulty that is 100% player optional. Want to do a challenge run where you limit yourself to really low stats? You can now do that.
2) Adds further replayability by making more "obscure" multi-classes feasible (TBD).
If Larian implements multi-classing per 5E rules, there are actually minimum stat requirements for multiclassing. For example, if you want to be a Paladin/Monk - you actually need a minimum of 13 STR, 13 DEX, 13 WIS, 13 CHA for the character to be legal. This build is basically ineffective if you are restricted to point buy, but could be pretty feasible if you rolled well.
If this game wants to try to have the longevity of its predecessors, I think giving options to allow more character options on replays goes a long way.
