The other part is that carbon fiber is good at handling expansive pressure (pressure coming from the inside of the vessel) and bad at handling compressive pressure (pressure outside the vessel).

It kind of intuitively makes sense. Carbon fiber is roughly like a fabric. If you make a tube out of a piece of fabric, there's almost no resistance when you try to compress it between your hands. There's far more resistance if you try to move your hands apart inside it, up until the fabric rips.

It was a terrible material for this to begin with between the risks of delamination and carbon fiber being specifically bad at the kind of pressure they were dealing with.