lordfirefox: I don't know. That's a question for the GoG Team themselves as I am just a regular user and don't have any insight on why the GoG team does anything. If a GoG person comes in here and states the same thing you did in the OP then I'll eat my words, preferably with fava beans and a nice kianti. :)
You could email them; I'm pretty sure they would back me up. As far as I know, DOSBox is at least
more stable than a Windows version running by itself, even if it isn't always 100% foolproof. I suspect the Windows version didn't work on all their test machines (of which there are about 35 - 40, iirc), thus they went with the DOS version.