My issues have never been the Micro USB cables, but the ports. They seem to often not be solidly secured into the device. (Amazon's Kindles' ports are pretty rock solid, to their credit.)
I know of no specific reason why this should be more common with micro-USB than with other connectors, but I've only seen it happen with micro-USB in person.
The real problem is we don't bolt the ports to the chassis in most cases, we just put them on the PCB with little bracing them in the direction of applied force.
See page 40: https://www.usb.org/sites/default/files/CabConn20.pdf
Then I realized that the three volts that were supplied from a pair of AA batteries was really more of a suggestion. That summer, lots of gadgets I had became "USB powered"