Well, let's try another example: Patty and Mildred Hill's best known song--far better known than the Zoo Song--has nothing to do with their legacy. I doubt that they can even be said to HAVE a legacy, since their (disputed) composition of [the melody of] "Happy Birthday to You" is known by a miniscule percentage of those who sing it. Or so I believe.

Or . . . Dave Van Ronk is hardly renowned for his largest seller, "Bamboo," which made him a small fortune (on a Peter, Paul, and Mary album).

They both made a lot of money for various people (and I'm very happy for Tom Paxton, too) but I don't think they did much for their composers' legacies.