BP's number one motivation is being profitable as a corporation. There are other lesser motivations, but they all must lead back to the number one motivation.
What happened when BP learned that BP will be responsible for every gallon of oil spilled? What do you think was the most effective way to address that threat to BP's number one motivation?
The answers are found in exactly what BP did. First, BP reported low leak numbers. Reporting higher leak numbers would cause BP to pay more money based on BP's own admission. BP became an instant compulsive liar about the amount oil spilling from the leak. The numbers were going up and down daily. It would have been comical if the implications weren't so dire. If you believe BP engineers know what they're doing, they you must also believe that BP knew the leak numbers were way higher than what BP was reporting. BP generally didn't fully cooperate with the U.S. government when the U.S. government wanted things like the best leak video and accurate stats about the spill. Second, and perhaps worse, BP spent millions upon millions of dollars on a public relations campaign, which included expensive television ads.
BP has not been doing everything possible to stop the oil. Doing everything possible would involve not partaking in the things mentioned in the last paragraph. Further, trust is earned via actions. BP's actions have proven BP to be untrustworthy. We have here a company that misdirected energy and resources that should have been used to fix the damn leak. For example, BP could pay more money to the best experts and/or pool the top engineering minds from around the world. BP may be doing some of these to an extent. However, when I see expensive damage control ads on television, the ads alone are proof that BP's resources are not focused on doing everything possible to fix the leak.
What would make anybody think BP is doing everything possible to fix the leak anyway? BP didn't do everything they could BEFORE the leak. For example, BP didn't develop leak fixing technology that was equally advanced as their drilling technology. BP should have. Also, BP ordered the use of sea water (cheaper) instead of drilling mud right before the explosions on the rig. BP shouldn't have. With such a prevalent culture of negligence, it's not possible for BP to be suddenly doing everything possible to fix the leak.
_________________________
If you're reading this, it's too late.