Actually, that's not from folks who sell glasses. It's from folks who produce fine wines, and want them appreciated. It's certainly been established in both single and double blind tastings at a highly statistically significant level that the size of the glassware and the degree to which the bowl concentrates the nose makes a substantial difference in taste perception of wines.

Even folks who have very little experience discerning differences among fine wines have been shown to prefer wines from large glasses tasted blind, where the bowl is shaped to concentrate the nose.