Ability score adjustments from your class are new to this edition (as far as I know), and I'm generally okay with that. It makes sense that training in your class would improve related ability scores.
Since each class provides you with a single choice from a list of two or three ability scores, perhaps humans could be given two choices from that list, but they can't be the same.
Overall, I've come to feel that racial modifiers should be an optional module. For those who want any concept to be viable, there would be no modifiers, and for those who want a simulationist approach, the module would include both bonuses and penalties with a human baseline.