Now if you really want unorthodox characters, the only way to be sure is rolling stats in order.I actually like doing that, although it almost never happens because I'm one of the few, but I'm definitely a "combat as war" type. I can still have fun with "inefficient" characters, although not every system supports them well, in some system where balance is assumed too much, "inefficient" may be too close to "incompetent".
Who wants those unorthodox characters? If the players want them, they can roll and adjust to point buy limits. So you could end up with that 16 STR, 16 INT fighter or wizard. But you don't get that 16 in the usual "off stat" for free - your wizard can't have the same stat array as the guy who optimized, plus bump your STR to 16 with all the advantages that carries.
If you want, sure, you can have less stats than the point buy would allow - but you have chosen to have a less powerful character than the other players.
Now, if the GM wants these unorthodox characters, it's certainly his campaign, but recognize that you are imposing your playstyle on your players. Will you enforce it - sit there, roll 4d6, drop the lowest, six times and no matter what you roll, that's the character you play? Will the players accept that? Most importantly, will that approach make the game more fun for all involved?