I suppose I think about it this way. The end of the contract will be dead weight regardless of how the player performs for the first half. I see the last 3-4 years as guaranteed overpay. Anything that lessens the chance of the player being on your team for those years is a net positive.
Maybe I am thinking about this incorrectly.
I think it depends on how you value the years immediately following the opt out. If you think there could be value there over the balance of the contract, the opt out has the potential to hurt the team. The way I look at it is that the player would never exercise an opt out unless they thought they could make more money, to me, that means that everytime an opt out is exercised and a player gets more money, the deal the player left was a situation where no opt out would have been preferable to the team