Bullshit. Some guys just say this cuz they don't wan't to be labeled a "chubby chaser", even if we're really not talking about chubby women, just normal, realistic body types. It's an immature, high school type of attitude where you're mostly concerned with your status among your so-called friends. Been there, done that, and wish I hadn't. I probably would have gotten laid more back then. I highly recommend ditching it and learning how an adult man speaks the truth regardless of how others view you.
your right about people not wanting to be labeled but everything to do with promoting products, events, or anything is all about slim/skinny women. You wont see a Victoria Secret commercial or magazine with plus size women. Everyone has different taste & should have it.