No, it's saying that people who claim to be able to identify which wines are "better" than others (and how they differ) can't reliably do that. Wine recommende

No, it's saying that people who claim to be able to identify which wines are "better" than others (and how they differ) can't reliably do that. Wine recommended to you by trusted experts is not better than just blindly picking a bottle. Or at least, that is not something you can "say with certainty" if you haven't tested it. (And if you do test it, the results are likely to surprise you.) An awful lot of the experience of wine turns out to be the result of your expectations of it.