U.S. Tortured Detainees And Top Officials Are Responsible: Report

The purpose of torture was not to get real or accurate information. It was to get false information.

Among the tasks it was used for (none about getting real intel, none for the "ticking time bomb"-scenario) was to set up a justification to attack Iraq. To link 9/11 and Iraq. To link Saddam Hussein to Al Qaeda.

The tapes would have shown that, and that's why they were destroyed.
Read the Article at HuffingtonPost