Why 15 psi max on pressure cookers?

Which brings us of course to the Mythbusters Chinese Popcorn canon

Bonus points for special guest Alton Brown.

Its not your standard Pressure Cooker, but hey its a pressure cooker. I get 145 psi for 1 MPa, so that gets you over that pesky 15 psi limit. I don’t think they carry it at Walmart.