Most of the community use those expensive computers with super powered CPUs, high amounts of RAM, Windows 7 Ultimate but an integrated graphics.
It'd really make no sense to switch the bullet physics to being calculated by GPUs, which in my opinion is a really stupid idea since Blockland can't do that anyway and not everyones GPU is good enough for that.
You're probably thinking of like PhysX or something, which isn't what Blockland uses.