Interesting post.

I would expect BA or indeed any "full-service" airline to be able to provide decently enjoyable wine on board in J or F.
But there is a big difference in my mind between enjoying a bottle of wine from a case that you have selected yourself, and may have come at some cost, at home with friends/family, and having something that pairs reasonably with whatever you are eating at 38k ft.
I find that my taste buds and sense of smell are too degraded at that level to make a huge difference between, say, different Bordeaux, so I am happy enough to take whatever the BA "Master of Wine" has chosen...

LPGS is nice but I am not at all one of the group of people who think it's the best thing ever, nor am I that bothered about finding airlines that serve Krug or DomP.
There are many times when I don't drink at all on LH or SH flights, either by choice or necessity.

Personally I am more interested in the Whisky served on the ground; I used to think the Singleton was fine, JW Blue is nice enough although I prefer a single malt if I can get it, Talisker Surge is a bit too smoky for my taste.
If I see a Mortlach 14 (EDI, GLA, LGW GF) or a Highland Park anything (BOS) then that would be a spot of good luck.
At the front of the cabinet at home is usually an Aberlour or a Balvenie 12, neither of which are really expensive bottles.
Again, in the air is less of an issue due to my being ineffectively discerning at that altitude. I'm sure I've had JW Red in CW cocktails- I'm still alive...!