There's definitely a chicken-and-egg problem of the current user and developer base of GPGPU apps being a very tolerant bunch. "It's just a flesh wound" they say about a lot of things that are prohibitive to normal app developers. Maybe it's the natural order of things, or maybe the the "incompatible proprietary C++ dialects with different kinds of crashy drivers on each OS" approach will be suffiently unpalatable to some future generation of programmers.