So, I'm riding behind my bud who's on his new 50/36 carbon bike, and I notice he's spending much of the time in the largest cogs on the cassette. I point this out, he shifts to the smaller ring, and then he's spending much of the time in the smallest cogs on the cassette.
I doubt it - the statement itself is illogical and statistically impossible.
A compact chain-set doesn't create chain-lines, nor select gear ratios - frames, BBs and cassettes are the contributing factors of resultant chain-line or gear ratio selections. Perhaps you could argue that compact chain-sets require multiple cassettes for optimal chain-lines in differing situations.