This was an accident. A greed motivated accident yes, but an accident nonetheless. This is a very deep well penetrating far below the crust of the Earth. We have little to no idea what's down there and BP just had to find out and get their hands on some of that (possibly endless supply) abiotic oil. No one ever dreamed that bore pressures could reach 20-70K PSI. The equipment was never designed for these pressures, nor does the technology exists to manage flow at these pressures.
Where do you come up with those numbers?
As an engineer in the oilfield industry, let me assure you pressures of 20-30 kpsi are commonplace. Their equipment was designed to easily handle them.
Google "Autoclave Engineers". They sell 60 kpsi plumbing components off-the-shelf.
But when you pursue shoddy practices in the name of economy - inadequate centralizers, using seawater where drilling mud should have been, allowing your failsafe device, the blowout preventer, to fail operational tests - you're an accident waiting to happen.
Think of an illegal driving a van at high speed with bald tires, shot suspension and faulty brakes and you'll get the picture.