Well, that is kind of the point that I was trying to make. Sorry if it fell flat. Sometimes making a stupid move is a necessary evil?
You mentioned Zito -- an interesting case -- because there's absolutely zero doubt that statistically speaking, his value was almost negative to the Giants throughout his monstrosity of a contract. BUT, putting his numbers aside for a moment, it's also worth looking at the other components of Zito (as both a player and a person) that might have provided some (perhaps negligible) value to San Francisco. They stole him from Oakland, which accounted for a great deal of the overpay, winning them points in the whole intra-city rivalry thing. The guy is prototypically Californian (surf first, think later,) and was a model citizen during his tenure with the team. He represented San Francisco's willingness to spend, and their desire to win. Yeah, he may have tied up money that could have been better spent elsewhere, but it never seemed as though the Giants shopped him agressively or were particularly hamstrung by his contract. And they won. Twice. Helps to wash away that bitter taste.