Speaking as someone who just started exploring Prolog and lisp, and ended up in the frozen north isolated from internet - access. The tools were initially locked/commercial only during a critical period, and then everyone was oriented around GUIs - and GUI environments were very hostile to the historical tools, and thus provided a different kind of access barrier.
A side one is that the LISP ecology in the 80s was hostile to "working well with others" and wanted to have their entire ecosystem in their own image files. (which, btw, is one of the same reasons I'm wary of Rust cough)
Really, it's only become open once more with the rise of WASM, systemic efficiency of computers, and open source tools finally being pretty solid.