I still think it's the same basic framework. "Benefits" is a highly subjective term. I think you are still making the same essential decision - is it worth risk X for new experience Y. I agree with you in the sense that I think very few people would actually decide to take a concussion just to experience an altered brain, but that doesn't mean it's not the same type of decision.

And to be fair to your point, although I think his analogy is apt, it is rhetorically misleading in that the implication is that you wouldn't want the concussions so you shouldn't want the drugs. In fact, I think that the asymmetry between his analogy and the drugs analogy serve to best demonstrate that the question isn't black-and-white and that it would be hasty to jump to the conclusion that everyone interested in brain function should rationally take mushrooms.