The structure of D&D is fairly flexible and allows for a lot, and should make sense at a broad level, but it's just as obviously fantasy: not a 100% accurate physics simulator. Giving a +1 or +2 bonus to an ability score is more than enough in my mind to reflect racial differences without getting into the complex, nitty-gritty details of biology and physics. Don't let the perfect be the enemy of the good.
At the end of the day, I do believe that you should add +2's or +1's to your hearts content, if that's what makes the game work for you. My point was simply that it is not realistic that way, or the way they used to do it, or the way they do it now. Its all arbitrary to a fairly large degree.
This is why I am not bothered by the change, though I'm not exactly thrilled about it either. No matter what the system is, any rules adhered to slavishly are going to act as a roadblock to fun at some point in time.
For what its worth, I like the Warhammer system better, where Elves and Dwarves have dramatically better stats than humans, but pay for it with restrictive social rules.
