For a start, Budweiser nor Miller would 'go' with what you'd have for Christmas dinner. You don't want something sharp, you want something with a bit more depth. A brown ale would work nicely, or perhaps something a bit malty. Fullers would work, for example.
People drink Budweiser and Miller because they are following consumerism, they are doing everything you are complaining about. I've treated people who exclusively drink those beers to other, more obscure ones, and every single time, without fail, the people have preferred what I've offered them.
I don't drink obscure, unknown beers. 99% of the beer I buy to drink at home comes from ASDA or Tesco. I only drink obscure stuff if I've been abroad, in a beer bar or am particularly flush and able to order from beersofeurope.
I'd argue that the majority of people in Glasgow have poor tastes, remember what Gordon Ramsay said about us?
I like wine, my father (who prepares our Christmas dinner) loves wine and is very knowledgeable about it. We think that it's worth buying a few lovely reds (we actually drink relatively inexpensive Cava and other fizz rather than Champagne) and are happy to pay the price for them as we think they are worth it. I'm well aware of restaurant markups, and buying wine when out for dinner is a total minefield but with a tiny bit of knowledge (about pairings) you can often pick something appropriate and something you can afford.
I'm not denying that there isn't a great deal of 'cheap' £5ish bottles of wine, and I'll often spend not more than that for a bottle for a night, or a dinner. However, on special occasions (dinner parties, birthdays, and especially Christmas) I think that it's worth buying a better quality wine. I'm sure you'll no doubt come back and say you've drank a £100 bottle and it was no better than a fiver bottle, and in some cases that may be right. But give the choice to someone who knows something about wine and the quality will be World's apart.
If Rotty, or whoever, wants to spend whatever they want then I'm sure it's because they think that it's worth it. It has nothing to do with consumerism, but individual tastes and budget. I've eaten the dirt cheap meat from ASDA (hell, I don't have much money so I do it quite often) and I've also eaten the expensive birds from there and I can tell you that they are a total different taste.
Our Christmas dinner this year is being made for 8, and I suspect the price will easily top a grand but my father can afford that and buys quality ingredients from local suppliers, and they unfortunately cost a bit more.