If I can oversimplify a bit, as Murakami-san say: You used to put up with the b.s. that went with working a lifetime in a large, bureaucratic organization. Now that the security & benefits are no longer assured, you see more mid- to upper-mid level workers willing to take more chances and start their own companies.

By no means should you confuse this as being any sort of sea change - the first post is still completely accurate for the majority of young workers, especially - but I think more people are starting to recognize "freelancer" & "self-employed" as something different from "freeter" - a Japanese term that ostensibly means "free + worker" but is really seen as just some young bum who bounces from one part-time job to another.