How overrated is Mark Sanchez?

I don't get why people think he's good at all, he had an offense most QB's dream about yet he was not even close to a pro bowl level. More people right now are criticizing Joe flacco than him right now yet flacco had a much better 2nd year with his best receiver being his running back. So honestly if you're the jets how much time do you give Sanchez? The jets are a team built to win the superbowl NOW and yes they have come close twice but more credit due to the defense and running game than their "franchise" qb