Same here: we use the cable that came with my wife's iPhone 5 on a daily basis and it looks pristine -- indeed I have no way of telling it apart from my year old iPhone 5S cable.
Meanwhile I have seen tearing on some of my old 30 pin cables, but considering some could date back to my 2004 iPod, hardly a surprise.
No idea what people experiencing this problem are doing with they cables, none, because I don't exactly baby mine.
I have 3 currently and two broken away.
I use the phone while plugged in charging so maybe thats the reason why but never happens with any USB cable ive used on other phones. Latest one thats broke is in the car so not sure how the rubber has come away off that one. I put it down to Apple cheaping out as its never happened with other USB cables like I've said, only lightning cables.