It seems that the design of the connection on the Fire is such that it larger than need be for the OEM charger. I have found that other cables in my collection have a better (tight) fit. Why on earth so many people are "wiggling" the cable connection? STOP doing this -- you risk making it worse!
I suspect people are moving the micro USB connection from side to side when removing it, rather than carefully pulling it straight out.
There is a better alternative. Purchase a better cable at Amazon for $3 and a 2.1a USB AC Travel (folding prongs) charger for $9.99.