Unfortunately, any game that includes melee attack ranges is going to be leery of creating an actually Large player race. Going from "I can strike 8 squares, or 24 with reach" to "I can strike 12 squares, or 32 with reach" is a HUGE buff for melee and completely useless (or even detrimental) for anyone that drops unfriendly AoEs, including other people in your party. That kind of wildly build-specific power, where it's phenomenal in one specific way and weak/terrible for anything else, does not play nicely with most ideas of game balance.
I'm not saying it can't be done. Just that "increase your melee target area by 50% and turn 10' wide hallways into hard chokepoints and 20' wide ones into soft chokepoints" is really, really powerful. That would generally mean the whole rest of the race probably needs to be ribbons and penalties, and would very likely be stuck typecast for melee bruisers (Fighters, Paladins, maybe Monks for grapple shenanigans, almost never casters).
There's a reason 4e gave us a Tiny race, but did not give us a Large race. Large matters that much.
