I see a dumbass construction so often that I now just gag, spew and go on. *sigh* Here’s the situation: a writer (or speaker) is attempting to say
“Some members of [Class A] are also [Class B]; some are not.”
But they write/say,
“All [Class A] are not [Class B],” as in, “…a distribution center was set up under a former S4 proving that all S4s are not lame-brain[…s].”
What the author said there is not what he meant, if the preceding text (wherein it had been asserted that S4s are characteristically “lame-brained”) is to be believed. No, what the author meant was very distinctly different to what he wrote, namely, “…a distribution center was set up under a former S4 proving that not all S4s are lame-brain[…s].”
It’s NOT a subtle difference at all. It is a profound difference. “All are not” is NOT “Not all are” by any stretch of the imagination. One says very plainly, “NONE of A are B” and the other says, “Some of A are not B.”
This kind of widely-spread lack of sense in writing and speaking says to me that those who use these formulations have a logic circuit that’s broken, or firing only intermittently. This sort of widely-spread butchering of sense in language is a definite indicator that popular culture is, simply and bluntly put, stupid.