What a load of hogwash.
First, restructuring does not necessarily mean a player gets paid less. Converting base salary into bonus money pays the player the exact amount as before, just now some of that money is guaranteed. It's always risky for a team, but it's a common tool to lower a player's cap hit.
Secondly, plenty of QBs have done it. Brady and Big Ben have both done it at least 2 times in the past 5 years if I remember correctly.
You actually just proved his point. Players move the money around, but they don't eliminate it completely. That's the point. His statement was that no QB has agreed to take a straight paycut, meaning no bonus conversion, etc. While I wouldn't say nobody has done it, I don't recall any big name, franchise QB doing it. Restructuring a salary into a bonus to create short term cap space is just like putting something on your credit card. It doesn't go away... you just pay it later. This is all moot on Joe, because only $6M this season would be subject to this anyway, so converting a portion or all of that into a bonus wouldn't even yield that much cap space. In short, its not happening.