However, I am becoming quite aggravated at how some people seem to hide behind it.
QFT
I'd quote more, but it smacks of wasted page-space. Ok...except I have to quote this bit:

they will freely and spontaneously change alignment, make up ludicrous backstories and come up with incredibly convoluted reasons that will allow them to play the latest build that caught their eyes. Quite simply, they don't play characters. They play builds with characters superficially tacked on to them.
Writing a backstory that coincidently covers and legitimises every bizarre feat/level/race choice on that optimal build list isn't roleplaying: It's just trying to justify a bunch of numbers. Trying to pass it off as roleplay is just laughable.