Why was shark canceled?

Shark was canceled because it's a GREAT show. And the always cancel the best shows. The networks must be out of touch with the viewing audience.

True, shark is a great show; however the main reason why it was canceled is because it hard to compete with CSI for viewership and it turned out that CSI was more popular which of course in my opinion I disagree.

Another reason is that people complained that it is meant for older people.