The complicating factor is, what is the incremental business that DL would get out of having a Sky Club there, not only in terms of additional flights but also Sky Club memberships? If you're already flying DL, what is the incentive for them to spend more money to accomodate you, unless you will give them more business as a result?
I really liked the old Crown Room at Denver (and the Horizon Club before that) but a fair amount of the time that I spent there was before boarding flights on other airlines. So I really can't blame DL for gradually restricting the clubs to hubs and major airports (e.g. LGA). At the same time, I have been hoping that the NW/DL merger would motivate DL to re-open clubs in some locations (such as MCI) that now have a number of additional flights.