What changed is that the very things capable of eliciting interest in programming also offer overpowering content consumption functions with huge, never ending catalogs of games, movies, videos, short funny clips etc.

As computing and "content" proliferate, the uncompetitiveness of creation, esp. symbolic creation such as programming, is increasing. At some point, broadening of the access no longer offsets this effect, and the talent pool may start to shrink even if capability and permeation is a million times higher than it was.