Think of the inertia that mag stripe only payment cards have in the USA, and think about how long it's taken to get chip cards rolled out. And then consider that we don't have the more secure chip and pin variant that Europe has, and (to the best of my knowledge) don't have any plans to go that route in the future.

A bad solution with broad penetration and huge network effects is one that can't easily be changed in the future. Let's do imagine some worst case scenarios and think about what it would involve to harden a system against them before rolling it out to everyone.