The question wasn't, Is giving up a walk worse than a hit?
The question is, given two pitchers who would both expect to have a similar ERA in a neutral park, which would be better for Coors? The control, higher OAV guy, or the walk prone, lower OAV guy?
Answer: walk prone, lower OAV guy. While every pitcher's ERA will increase at Coors, the latter player's will increase to a lesser extent.