It was revised to fail at 5000 MTBF, much more acceptable for something that may be plugged in multiple times a day.
Micro USB was rated I believe at 10k MTBF, and moved the faily bits to the cable.
The USB-IF obsoleted the Mini-A and Mini-AB plugs at that point (which are really only used for USB-OTG, which is rare). They still let the 5k MTBF mini sockets get certified on new devices, however.