Actually, that is what they teach at university nowadays in race and gender studies departments, sociology, and other mushy social-sciences. My friends who went to places like Harvard all believe it.
It's not a "belief". It's just predicated on an alternate definition of the term.
(Unfortunately, many people on learning an exciting new definition of a word forget it has a more general meaning; confusion and stupid internet arguments ensue.)
Care to elaborate? I think that's a misrepresentation of critical gender and race studies, because I happen to be in one of those very programs. I won't deny that it's a "mushy social science", but I think you're radically simplifying the field.