Archievements are primarily a huge violation of privacy, and a basic violation of computer security principles.
So no thank you.
If at all, they should be optional.
Also archievements need a server. I dont run the GoG server. So theres no technical possibility for having archievements anyway.
And down. And up ...
Personally, I think I'd rather have DRM-free games than achievements...
I need archievements about as urgently as somebody poking me in the eye.
I don't really care about DRM if it doesn't intrude on the gaming experience, and if it can't be used to prevent me from installing and/or playing the game whenever I want.
DRM by very principle always interfered with the gaming experience. You always had to look up your CDs, and if the CD ever broke ...
Online is even much worse, since at times you may not have an online connection, and have no control over that whatsoever.
GoG is heaven.