You're missing the point: of course it's not in BP's interests to have a well explode, but the people making the important decisions are often not making those decisions based on sound engineering, but on political pressures and incentives from above.

Richard Feynman showed an excellent example of this after the Challenger disaster. He was on the Presidential task force after that disaster, and he asked NASA management and engineers, separately, to quantify what they felt the odds of a catastrophic failure resulting in crew loss were prior to the disaster. The risk values quoted by engineers and by management were something like 2-3 orders of magnitude different (with the engineers quoting the much more likely value)...