Certs have existed a long time, are never implemented correctly, and the expiration cycle that is supposed to bolster security just causes pain as a result.
Certs should just be redesigned to have a kill switch. CRLs were supposed to handle that, but are rarely implemented or implemented correctly.
Certs are also used in so many places where they may not be suited to the task, but because they exist, they've become the de-facto standard.
A temporal expiration system seems flawed from the beginning anyway. What, you don't trust your system anymore just because time has passed? Time is always passing. Are we all secretly racist against clocks now?