Mmm, whilst this is certainly true ... both that we often forget and that indeed these places are just lounges, there is considerable scope for providing services to frequent customers which should not be breaking the budget yet still give your most important customers yet another reason to enjoy using your services. There are many lounges to be found internationally which provide very good services for business class or elite guests, including a good variety of hot foods as well as cold and deserts, drinks, etc - these types of superior lounges make choice of airline really easy for a FF.
On the other hand, I guess its so often simply good enough to match a competitor in a particular marketplace ... I mean, where is one going to go when travelling domestically? QF? The food/lounge offering is certainly no better. Leap across the pond to pretty much any part of Asia and beyond and the competition is fierce, meaning that customer service and the _real_ desire to retain high value customers is more than a meaningless line on a strategy sheet.