He's the third highest rated quarterback ever. Last season he completed 62.3% of his passes and threw 27 touchdowns. He threw for at least two TDs in each of his final eight games last season, and threw three TDs in five of those. And this guy is getting benched for a QB that's never done anything in the NFL?
OK, I get why teams usually favor a recent first-round draft pick at QB over a successful veteran. When the 2004 Giants replaced Kurt Warner with rookie Eli Manning, it was bad news for the 2004 Giants, but the 2005, 2006, and 2007 Giants made the playoffs. The Bengals replaced Jon Kitna with the unproven Carson Palmer, but I think most of us believe Palmer has been and will be better for the Bengals than Kitna was. And the Chargers likely would have been great if they had kept Drew Brees, but when they let him go in favor of unproven Philip Rivers, they won 14 games the next season, and went to the AFC Championship Game the year after that. Sometimes replacing a solid veteran can be the right long-term move.
But goodness, Matt Leinart is doing what he can to get moved to third-string. The strength of the Phoenix Cardinal's offense (yeah, I'm calling them the Phoenix Cardinals again) is their incredible wide receivers, Larry Fitzgerald and Anquan Boldin. They absolutely need a quarterback that can utilize their skills. In the NFC West nine wins could take the division title, and in the NFC it likely means a playoff berth. I would think a team that has made the playoffs six times in its history, once since 1975 and not at all since 1998 would want to do whatever it can to make the playoffs again.
Free Kurt Warner! He's the best player for the Phoenix Cardinals right now.