Not everyone was meant to squat deep, but a simple test will tell you how deep you can safely go. And if "butt wink" is a problem, there are easy ways to fix it.
Matt Phelps is hugely pissed about the term "failure" and what it really means. He thinks exercise physiologists have one idea while the guys in the trenches, i.e., the guys in the gym, have a different, more realistic idea.