I think the reasons for the limited beverage selection have been explained quite well by AS Flyer and others. It's just not practical to carry more than a couple of different types of drinks on small planes and short flights. (I will concede that longer flights, like PDX-OAK, probably do deserve something more.)
So, the question is then whether QX should eschew the beer and wine in favor of more traditional drink service (maybe Coke and Diet Coke or orange and apple juice)? A few FTers have posted that they'd probably prefer that (as would certain FTers who have yet to be of legal drinking age...
). However, QX's market research probably indicates the uniqueness of their current offering draws more people than are turned off by it. Therefore, I don't really see any change in the future.