This is so screamingly correct. Let's go see the startups hire some old COBOL (or now, VB) programmers and train them on the new stacks, before we listen to anymore of this "there's not enough programmers in the USA" garbage.
Coming back to retraining, I think some of us in the bubble lose fact of how much dedication is involved to successfully learn something new and become productive. Retraining is hard and, more importantly, not everyone wants to willingly do it.