Every stat increase is also not made equal. Charisma‚ for example‚ does litterally nothing if you don't have SLAs or other ways to exploit it. And going from +24 to +32 in Str is way less impactful than going from -8 to +0 in Int. In one case you increase your damage output even more‚ for a creature that should already hit most of the time‚ +4 to damage per hit is really not that great (or +8 if you consider that all the bonus you get is going into Power Attack. That's not negligible‚ but not game changing either). On the other hand‚ the intelligence score means the difference between being able to contribute effectively out of combat or be restricted to 1 skill point per level out of a pitiful list.