They don't care as much, so it isn't a "great" contract for a cap team, which was the discussion. All things equal, if two players have the same AAV, are equal in talent, then sure the cap team would prefer to pay less for that player.
But the Chicago's of the world don't give a rats ass about the actual salary of the contract, they care about the AAV and which players they won't be able to sign or have to trade away to stay under the cap.
Teams like Arizona, Carolina, or any team who isn't projecting to be close to the cap, won't care about the AAV, only what the $$$ will mean to the bottom line.
It is pretty simple logic, actually.
Case in point, Ducan Keith made $7.6M with a $5.5M cap hit in 2014-15.
Myers made $5M with a $5.5M cap hit in 2014-15.
They both have the same AAV. By your logic Myers is the contract teams would value because the salary is less than the AAV.
Keith is the better value for Chicago because they are a cap team so AAV matters most to them. Keith gives them better value for that $5.5M cap hit in their Stanley Cup year (and his Conn Smythe win) than Myers would have. That Keith contract is a great contract for Chicago. Its higher salary than AAV allows the Hawks to fit and keep more of their stars and players under the cap, while giving Keith fair value in actual salary.
It would't be as good a contract for the Jets.