Why are people blaming BP and not Haliburton?

Quite. In a decent world everyone involved in that decision in any way would have been fired and civil action launched by BP to pauperise every last one of them.

Something absolutely draconian has to be done until companies and individuals working for them get the message.

I favour an ‘International Financial and Economic Crimes Against Humanity’ treaty with unlimited sentencing powers.

Hundreds of Masters of The Universe should be waiting their turn in the Hague as well as all the BP senior management and directors.

It sounds to me like exactly the right thing to say. BP was in charge, therefore BP is to blame, pure and simple. Now, the deeper questions, such as where specifically the failure or failures were, which companies and/or personnel made the decisions that led to those failures, etc. can only be answered after sufficient investigation. The answers to those questions are very important, and should be used to put procedures or requirements in place to prevent this kind of disaster in the future. But those answers are completely irrelevant to where the blame should go: It goes to the one in charge, which is BP.