Francois,
I've seen some Obj-C code and it looks really weird. Of course I've never 'learned' to program it so it's probably normal. But it's certainly the case that only developpers who know Obj-C can work on it. Contrast this with the current situation where as soon as you know C you can work on any area of Wine.
Look, anyway Obj-C is supposed to be used in Wine only for Mac support, and not for anything else. Any developer that knows how to program Mac knows Obj-C so there's nothing wrong with constraint that only developers that know Obj-C can work on it, because those are guys that know how to program Mac. Or by contradiction... even if the code was written in pure-C, non-Obj- C developers wouldn't be able to work on it anyway because they wouldn't know OSX API and wouldn't have Mac machine for development :)
That said, from the sound of it it does really look like Apple is pushing Obj-C so maybe we don't have much choice in the matter.
It's not really about Apple pushing Obj-C, but about Obj-C being a foundation of the OSX and Next operating systems, while not being as popular as C++ just because Macs doesn't share so much of the market as Windows, where C++ gained its popularity, thanks to MFC, Borland, etc.
I'd gladly help writing native Wine Mac support, but I don't want really do it hard way using obscure excessive C code, but do it in Obj- C. I do respect my own time and pure-C way is in opposition for that.
Regards,