The "let's pay twice as much in rent and operating costs to avoid giving club members better food" idea that AA/UA have never made a ton of sense to me. For a long time, I've suspected based on what I've read online that American Express pays Delta per Sky Club entry for unbranded Platinum and Delta Reserve cardholders, which is part of how DL was able to set the Sky Club up with better food than AA/UA have -- their incentive structure is to provide lounges that people won't skip.