The oversight is a joke. The CIA tortured people throughout its history, including following 9/11; what oversight did they face as a result? What were the consequences? More funding for running their drone program?
Torture was the official policy of the government. Oversight wasn't the problem, it wasn't rogue CIA black ops. Don't confuse lack of oversight with policies you don't like.
Torture is illegal under international law, and it is unconstitutional. It cannot be the official policy of the government, which is why they tried so hard to pretend they weren't doing it.
You are talking about how things should have been, not the reality. Reality was that it was explicitly policy, they weren't hiding it, they were rationalizing it. You can read much of it yourself:
