I’m reading his post the other way around: I think he is bitching and moaning about having to offer a lot more money to attract somebody from the competition.

The situation were somebody has already chosen to leave and the opde employers offers more money as a last ditch effort to keep that employee is a whole different affair with, as you pointed out, the whole element that them offering you more money when you’re about to leave means that they’ve knowingly been underpaying you all along.