It's become so common place now that it seems to be the norm.
If I say to someone "how are you" or "how're you doing" or something similar they invariably answer "yes I'm good thanks" or "yes I'm fine".
What is the "yes" for? I know it might make me sound trivial and pedantic but I hate it. People didn't used to speak that way. I think Eastenders started it off and now it seems the whole world does it. AIBU?