The approach would essentially cut the oxygen supply from one source. Trouble is, Lyons notes, there are others with a tank and mask. If one won't supply things freely, others likely will, and that would isolate those who choose not to play ball.
Essentially what he's saying is that if everyone doesn't do it, it won't work. And what he and Cuban agree is that it's unlikely organizations will try. It's a risky move to cut traffic, watch your rival gain at your expense, and hope subscription revenue will offset the advertising decline that goes with the fewer page views.
As Lyons notes in the piece, no one has even been fired for pursuing conventional wisdom.