[jacquesm]

The hardware was designed to display triangles, not to do 'Hello world'.

So it's not all that surprising that the one is easier than the other, in a way it is surprising that the other can be done at all. But as CPUs and GPUs converge it's quite possible that NV or another manufacturer eventually slips enough general purpose capacity onto their cards that they function as completely separate systems. And then 'Hello world' will be trivial.