Here's the thing... Bottle Service when you work in a restaurant can be a mofo. Scraping the wax/whatever off of the bottle and then having to uncork the bottle at the table and pour a "sample glass" for each person so that they can try it & make sure it tastes ok... It can be time consuming. And then if the guests decide they don't like it (I've never had that happen, so I don't know the protocol for it)..

Aside from that, alcohol in a higher-scale restaurant is usually grossly overpriced. Especially wine. That $40 you spent on a bottle in the restaurant probably only costs about $15 - $20 in a liquor store. Granted in "cheaper" places - like Logan's Roadhouse, they have happy hour and you can get a glass of uh. like. White Zin (Gag me now) for $2.