Beer snobbery and Gnosticism both have at their core the belief that certain truths are incapable of being appreciated by all.
This is a form of Gnosticism because it holds that "certain truths are incapable of being appreciated by all"? It only holds that "certain truths are being incapable of being appreciated by all" in the sense that the cartoon argues that a lot of Christians misunderstand the true value of Christianity. so, basically: "All craft beer drinks are snobs. Snobbery is an aspect of Gnosticism. Therefore, all craft beer drinkers are Gnostics"?
I don't think I need to explain why that's fallacious.
My argument is more like "Craft beer drinkers are snobs", "Gnostics are snobs" "Belief in snobbery as a good thing in one area makes other types of snobbery seem better." Hence thinking craft beer drinkers are better makes gnosticism appear to be better.