My objection to "if you can't talk right don't talk at all" lies mostly in the realm of people who aren't hip to the current lingo, or who don't feel competent to become hip to same, but who in their clumsy ways are still trying to say things I agree with. (My parents, for instance.) It bothers me when incompetent speech is automatically assumed to be cruel speech.

I disagree with you in small ways about how language works, but it's the kind of hairsplitting that's not worth the typing in comparison to our general agreement.

Great, now I have to go do my laundry!!