Subtle? Nothing subtle about it.
You said something about it being flawed, got challenged to demonstrate why it is flawed, responded by making a vague statement about 'lots of external factors' which is irrelevant to the question you got challenged on and you blabber out something about a counter-argument, only to finish off by asking me to show you how it works after you've stated it is flawed!
There is no argument thus far. I'm not arguing anything. I'm waiting for you to present a shred of understanding of the metric and tell me how it is flawed like you said it is.