It may or may not be true that "Whether the critic smokes or not will have a direct influence on how that critic scores wine." But it's irrelevant.
What matters is how consistent a critic is, and how closely your palate correlates with the critic's opinions. If you consistently like the wines the critic likes, what difference does it make whether or not the critic smokes or not?
One might wonder how drinking coffee affects a critic's palate, or chewing gum, or a regular habit of indulging in spicy food. Most likely, all the things we eat and drink shape our perceptions of flavor. It's impossible to tease out the specific impact of a single factor, whether it's an occasional cigar, a fondness for single malt Scotch or the love of a woman who uses a particular perfume.