Not all women are bitches, and not even all bitches are women, but the bitches that be are, in fact, crazy.
The correct reply upon hearing this is to echo it back in confirmation.
guy2: Dude, bitches be crazy.
guy1: Bitches be crazy.
Sean: Bitches be crazy, lets go get buffalo chicken wraps
Matt: Wow....... You changed my life forever.
Jordan: "Well, you know how it goes man..."
Marcus: "Yeah, bro..."
Jordan: "Bitches be crazy."
2. Usually muttered in the company of women, which creates a hostile response bordering on insanity, thereby proving the theory
Matt: "Bitches be crazy..."
Jamie: "What!? Fuck you! I'll cut you you son of a bitch!"
Matt: "Thank you for proving my point."
This is why women are illogical, because they are crazy.
Me: Because man, Bitches be Crazy