>People always talk about Moore's Law falling apart, and it seems like people didn't see it coming.

First of all, let's be more precise. In this context, what people mean by the "end of Moore's Law" is the slowdown and, soon, probable end of CMOS process scaling. The issue is that CMOS process scaling has been such an incredible engine for performance that just getting those kinds of performance increases in other ways isn't easy. I wrote a bit about this a year ago.

http://bitmason.blogspot.com/2016/01/beyond-general-purpose-...

To answer your question, people did see this coming. There were disagreements about how far down you could economically drive feature sizes so there has been debate about exact dates. But pretty much no one thought CMOS features could be made arbitrarily small.