... Why not openCL?
I don't understand that, there are more of 38% of ATI owners:
http://store.steampowered.com/hwsurvey/

I believe that OpenCL doesn't get to have access to texture memory. That would make it kinda worse than useless for this job.

OpenCL wasn't as functional back then when they implemented it, so they used CUDA.

You're right, i forgot it! I just hope it will change in a near future!
It's very frustrating, this patch is really working perfectly for me, include with textures in 16k, no freeze, no hang, no bug, but i can't use detail texture with my Q6700@3Ghz without getting constant framerate drops.
I think it should be better to reconsider original textures ( for near objets) than to try to enhance it, it's my opinion.
When u go in the secret room of id, u can find some very high quality texturing, without enhancing, why not this everywhere?
The poor space on a DVD is not an argument for a PC who can download everything.

The game still had to be released on DVD's aswell (physical). Besides, many people have bandwidth limits and/or relatively slow internet. It would be ignorant to release a game only the top-end could play.

It isn't even now
AMD OpenCL drivers are plain [censored].