It happens when the current programming languages fail short of solving the most difficult problems the industry faces and programmers explore some paradigms that solve them nicely, but those paradigms haven't been integrated into a single coherent platform.

This shift is pretty much happening with reactive functional programming - which solves asynchronous calls in the web -, and to some extent with large-scale module composition, which still lacks a good widely known solution.

Someone posts something on x obscure subject and people find it interesting and then research x on their own and post about x a lot.