Geography. The replies I've read, as they so often do, ignore geography. SV might move rapidly from one to the next, but the city I'm in is more conservative and moves slower, so all I've ever seen much of from recruiters are jquery, knockout, angular. SV is the gladiatorial arena, and only the survivors make it through the filters to elsewhere, so elsewhere has fewer to deal with. If you engage with SV news while living elsewhere you'll still be trying to keep up, but if you hang back, things are a bit more laid back. Or, make the decision to ignore every other tech. If the next one is along shortly, you'll not likely miss much.