This is powergaming, nor are we in it.
Personally, I think the "encouragement to powergaming" could also be called ... "having options". Previously, honestly, earlier versions probably encouraged more "bad behavior" about stats than this edition primarily BECAUSE there were fewer options ... You were a "Wizard" with high or low stats ... and you stayed a wizard, with high or low stats, for the next three years on your way to 12th level.
I mean, in my personal gaming experience, I've certainly seen fewer "mysteriously high-statted" characters in 3.X than, say, 2nd. I saw alot of fighters with 18/00 Strength ... far and away many more than is statistically POSSIBLE given the sample size.
Earlier editions, there really wasn't any "point" in playing, say, a 14 Strength Fighter as opposed to an 18/00 Str Fighter ... even if that 14Str guy had higher Charisma and Intelligence and Wisdom. Other than "roleplaying" ... which you can do with any character. Now you can build an effective multiclass, or you can qualify for feats that require Charisma or Wisdom or Intelligence that you couldn't otherwise, that makes the character different from other characters of the same class.
It might be powergaming, but it's more fun to me than saying: "This fighter, with his lower strength and higher intelligence than my last guy, Smashdor Ironthews, will be more intellectual about combat ... I swing ... I miss ... I swing ... I hit."
Now, at least, I can take Dodge and Improved Disarm and Combat Expertise and also get some mechanical variation to go with my roleplaying of Smartdor Brassthews, the fighter with 14 Strength.
--fje