You know, I've been wondering about this myself, though I'm not sure it just applied to fine dining for me.
I used to get a buzz out of eating at 'fancy' places and drinking expensive wines and spirits, all up to the point where I even splashed out on a meal at Al Mahara at the Burj Al-Arab.
The thing is though now I'm not sure whether I've just become a snob or the places I've been eating just haven't been up to scratch. I always manage to nitpick and find something that I dislike and overall I feel lesser for the experience and far lighter in the wallet. I've found the same thing has also occurred with some of the premium travel I've been doing - I'm just not blown away by anything anymore.
However, I've always been able to appreciate good cheap food - especially street food - and I've come to the conclusion that you're able to appreciate things more when you've paid so much less for them and they've far exceeded your expectations...
I don't know, just my two cents but this topic definitely caught my eye because I thought it was just me becoming a snob