Look at the end of the day hindsight is 20/20. The Panthers were in need of a QB and Jimmy Clausen seem no worse than what they had and due to his youth, it seemed like a good idea. People forget just 7 years ago, Jimmy was the #1 QB in the county, he went to Notre Dame and despite his iffy performances in the big games, had very good stats. The one thing he really messed up on was leaving college early, he really needed an extra year to marinate.
Keep in mind, Jimmy Clausen was considered a 1st round talent on paper and people had him as high as the top 10.
Dude is still fairly young and he can develop into a decent backup still. That's just life, some shyt doesn't work out.