Why's Clojure the top paying programming language?

Short answer: (language) sampling bias.

Because almost no entry-level programmers are coming in with clojure.

Same goes for F# and Elixir.

Most folks in these three languages have a lot of experience under their belt, and so they can get commensurate pay.

As a guess: small communities simply have larger variances, and we only notice the high-paying ones. (Same principle as when there's maps of rates-by-county of something or other in the US and all those empty counties in the west stand out for being super high or super low).

Normalize the data by years of development experience and country of origin.

Is there any big corp using it massively? why the shift up? It's kind of curious that a lisp is at the top of the list (according to SO). Not surprising, but curious. What do you think? any ideas?

Another, less kind answer: it was the flavor of the month about a dozen years ago, some devs decided to build everything in Clojure, now the software that runs entire large companies is in Clojure, nobody knows how to maintain it, so the only ones left over take large salaries. It's kind of like COBOL in banks, except it was hype driven and not we-had-no-other-option-at-the-time driven.