Micro USB is so small with the tiniest pins for 1A or more to flow through.

I just want to say the tolerances on the micro USB ports I've used (nokia ones) are very close. The fit is very snug. So, maybe in those mating cycle tests there is the understanding the mechanical purchase one might have on the socket is taken up by the socket rather than the interface as is the case with bog standard full-size USB ports. You know, the full-sized plugs float around in the socket. The snug-ness of the micro USB connection might prevent damage to the actual pins? Just a thought..