We're not necessarily in a bubble, but perhaps there's some foam?
There will be a plethora of programmer jobs for some times go come, but we've also gone quite a while without a meaningful market adjustment, if you will. A point may come where global politics force the industry to be far more regulated than it currently is, and the days of being a self-taught coder with no degree and a poor understanding of security may come to an end.
Maybe that doesn't happen, but if it does, I see lots of jobs disappearing and evolving into new ones, and a fraction of people in software deciding it's not worth it anymore. The world has only just started to truly realize how we effectively control information, and if the sentiment towards Silicon Valley gets worse then there may be more calls for regulation and new regulatory bodies; in which case jobs may open up within that new bureaucracy.
That hypothesis is irrelevant if the industry was operating at a moderate pace. There's a lot of money still coming from somewhere, and backpressure can create a wave that pushes revenue back in the opposite direction, if even briefly.