Calvin is an actual Boy Scout in some of the earlier strips, but Watterson abandoned this when he realised that Calvin wasn’t the sort of boy who would willingly join such an association, as he much prefers his own company (and that of Hobbes).
Many of Watterson’s strips were rooted in his struggles against the syndicate for control of the rights to merchandise C&H. I’m sure that today’s comic is one of them, as it implies that many people (his fellow cartoonists included!) will do anything for enough money, even if it compromises their integrity, artistic or otherwise..
Of course, Groucho Marx would never join any universe that would accept him as a member.