Although some academics (like myself) are intrigued by them, APL-like languages (APL, J, K, Q, etc.) have very little to do with academia historically, and were developed pretty much isolated from the academic programming languages community. APL itself does have distant roots in academia, growing out of notation Iverson developed at Harvard in the 1950s, but its history as a programming language goes via IBM and a variety of other companies generally focused on enterprise and finance (I.P. Sharp, Morgan Stanley, Dyalog, Kx Systems).

As for J, it was released by a startup, J Software, founded by Kenneth Iverson and Roger Hui in 1990 for that purpose. It was later open sourced in 2011.