Yes, there was a huge market through Y2K and the dot-com bubble for people who knew how to operate a keyboard, and that market collapsed. But those people where as much developers as I am a surgeon because I know how to apply a band-aid. Personally I was glad the bubble burst, because it became increasingly harder to avoid landing in a place where most of the "developers" weren't utterly incompetent.
HN isn't a representative audience though. Most of those people wouldn't be on the early 2000's equivalents of HN either. If this is a bubble and it bursts, most of HN-ers that get affected won't be out of work for more than a month.
Many may have to take a boring enterprise gig, but that's pretty much how the second wave of internet-companies started: bored and with time on their hands, many hackers started to work on what was then called "social software" projects, which eventually resulted in a wave of social media startups.
Things may be different in SV, especially when it comes to the balance of wages vs cost of living, but SV is an outlier.