They probably felt their finances couldn't the extra $10,000 or so (just guessing on the amount; could be more, could be less) they'd end up paying over the life of the loan for either the Enclave or the Acadia. Or they wanted to use that money toward something else.
The analog clocks are classy looking, but their practicality is debatable. They're practical for people used to analog clocks in the car dash, but they're a problem for people used to digital clocks in the dash.
They could probably have gotten the top of the line Chevy trim for the same price as the base for either the Enclave or the Acadia, though. For example, I have a top of the line trim in my 2011 Ford Fusion, and that means heated leather seats, the full Sync system for 2011 (minus the picky MyTouch interface), 2nd best stock audio system available for the Fusion (another one from the same year I was looking at had a much better stock system as well as a sunroof), fog lights, more compartments than I know what to do with, rear and front cabin lights, separate passenger and driver side climate controls, and decorative interior lighting, among other features I don't feel like listing. And it was still cheaper than a similarly spec'd Lincoln MKZ or Mercury Milan would've run me (neither of which I like the grills for, anyway; they feel too dated in styling).