He would be losing out on a ton of money just by leaving, not to mention the 1 year on the discounted QO. If he's ok with that, along with the injury risk that could cost him millions more, then good for him.
Maybe he does, maybe he doesn't. That's the point.
For the best players in the league (and most marketable), endorsement money can often eclipse your annual salary, especially over the long haul. LeBron James makes
far more money in endorsements than he does on the court - it's why he doesn't give a damn what city he plays in, money isn't the issue! Guys saying "he left money on the table" don't get the full picture. He
made money by leaving Cleveland, not the other way round.
Kobe Bryant has raked in hundreds of millions of dollars, not simply because he was the best player (because for much of his career he wasn't, Shaq was), but because he's in Los Angeles.
If Irving thinks he is potentially missing out on endorsement revenue by remaining in Cleveland, then it makes sense that he would have an expectation that Cleveland would be willing to pay max money early in his career in order to keep him here. If Cleveland is not willing to offer him a supermax 5-year extension and instead wants to wait (injury risk to Irving be damned) to offer anything but the Rose Rule max (assuming he qualifies), then Irving would have every right to want to leave and I wouldn't blame him.
But with regards to money, players like Durant and Howard (I use them because people will moan about LeBron and Kobe) have made tens of millions of dollars in endorsements due to national exposure and having a likable personality. In 2011, Dwayne Wade made equal amounts in salary and annual endorsement revenue. In that same year, Melo and Amar'e both raked in $8M annually in endorsement deals.
So what's the point? The point is that if Irving goes to New York or Los Angeles, he's likely to be their franchise player. In such a situation, he may be offered up-front deals to compensate for any loss. Kyrie has to be looking at his current endorsements, which are many, and wondering if he can't get better (higher paying) deals in the same way Jeremy Lin did when he went to the Rockets.
Cleveland should not put itself in such an easily avoidable position by not locking up it's franchise player now, simply because we happen to have the #1 draft pick who has yet to play a single NBA game.