Ouch... Why the hell have Cvet used DiectX? OpenGL is better ;p
Well i think we gonna stay on wine in that case. So bad.
Having used both, I don't agree. OpenGL is a bit more difficult to work with (C-style syntax, while DX is OO), and you have to write everything on your own, while DX comes with a lot of handy loaders. Also, it supposedly performs a little better on some graphic cards.
Of course portability is large plus, but productivity is sometimes worth more than supporting 0-2% of the userbase.