He has had 2 good years as a starter.
He is 30 and he has 2 good years.
A 6 year $100 some odd contract means that not only are you expecting him to TRIPLE his number of good years but do so as he gets deeper into his 30s.
When Brandon Webb was 29 he had won a Cy Young Award and had two second place Cy Young finishes between 2006 and 2008.
He looked like a great choice to lock up to a big long deal.
He's pitched one game since he turned 30 in 2009.
Johan Santana looked like he was putting together a Hall of Fame career. He had won 2 Cy Young Awards (and probably should have won a third) before his 29th birthday. He was 200 innings in the bank and an almost lock for the ERA title.
He missed all of the 2011 season at age 32 and his career is in jeopardy.
By age 26, Jake Peavy was a Cy Young Award winner with 2 strike out titles and 2 ERA titles. Since turning 28 he has thrown three injury plagued seasons.
At age 28 Barry Zito had won a Cy Young Award, was one of the most durable pitchers in the game and had experience in 5 different post seasons. By 30 he was an expensive and unreliable behemouth who was left off the playoff roster in 2010.
Every pitcher I just listed was a MUCH better bet to sign to a long term deal than C. J. Wilson.
Try learning from the past!
I said it before and I'll say it again... STAY AWAY FROM C.J. WILSON!