I've done quite a few as part of courses, and I've also served expensive bottles to people without telling them. It's definitely a humbling experience and the most expensive wines are certainly not always the most liked, but that's why you study: to make sure that you don't just buy ostentatious expensive stuff, but that you buy expensive stuff that is actually good and noticeably different from supermarket wines.

I'm guessing your reply is motivated by the 2001 blind tasting where oenology students couldn't even differentiate between red and white wine [1], which is certainly an interesting bit of research, but not the kind of slam dunk you would think when you read third-hand reports about it in the media or rationalist circles.

[1] http://www.daysyn.com/Morrot.pdf

This is almost certainly true. Professional wine reviewers fail taste tests all the time.