I have never had an issue with connectivity with any micro USB cable for my 2012 Nexus 7. I have USB cables from various devices that I basically use interchangeably. The USB cables are from a HTC phone, 1st gen Droid phone, Logitech mouse, 2nd gen Amazon Kindle, etc. I have no issues with loose connections for any of them.
However, I will save that the Amazon USB cable is the worse because after about 18 months the rubber started to crack off. It's still useable, but the inter-weaving shielding wires are now exposed.