That large format is pricier than 750ml. It didn't used to be that way. That and busloads of rude people showing up at the tasting room just when I'm getting into a good conversation with the staff.

Inappropriate serving temperature, overfilling the glass, and drinking wine fom plastic/styrofoam cups rank right up there... No, I don't think these are any signs of snobbery, but rather of good practices aimed at maximizing the wine drinking experience.