There's nothing surprising about the steady increase of popularity of VST's. They're pretty damn cool!
What is surprising is the sudden resurgence of hardware modular synths. When I started building mine in 2005, there were roughly 13 manufacturers, ie. Doepfer, Buchla, Modcan, Cyndustries, Wiard, Blacet, Metalbox, Serge, .com, MOTM, PAiA, Analogue Systems and Analogue Solutions. Many of these had been around for several years and interest was steady and somewhat low.
Now, seven years later, there are 60+ ...that's astounding for a market segment that's existed since the 60's. Hence the documentary.