Thing is, even if you completely ignore wine flavor there is so much to talk about. One, wine is often grown in picturesque areas that make great travel destinations. Wine has it's own battles like oak vs. no oak which brings people to same level of arguing as vi vs. emacs debate. If you're at all a history buff, wine intersects all throughout. Then there are generally cool, geeky things about wine. For example, how the wine in Santorini is cultivated is fascinating: http://www.winesfromsantorini.com/the-vineyard.html

I don't find any of this pretentious, and more general interesting conversation.

Indeed. They should be discussing something everybody agrees is important, like the relative merits of various programming languages or vi vs Emacs.

> "why is this so important to you?" territory.

You mean, "terroir".

Again though how much length is it really and how much length is it you mentally adding because it is for some reason important to you that it shouldn't be important to them. And by 'important to them' I mean: 'discussing the activity while, and only while, they are currently doing it'

Well I don't consider parties to be all about what is being consumed. Sure, it is while they are doing it, but typically a party is a generalized social occasion, not an activity based get together like a book club.

Is there no topic that you like to discuss at length, that others don't enjoy and wonder why it is important to you?