Thank you, you are correct. Stats should only be a minor point in evaluating things.
The amount of variables in a given set of data can be enormous and will affect the outcome and misplace the outliers.
For example, here are some important factors that do not go into a QB's rating. A QBR is just raw data subjected to a defined method of calculation....nothing more.
1. Quality of the O line. Did he have all day or ran for his life.
2. Did the QB have a running game? If not, being forced to pass will certainly hurt his rating.
3. Quality of defense
4. Quality of his WR's
You get the idea. In short, should Brady, who usually has excellent protection and a mature WR core, be compared to the QB for AZ. who has a horrible O line and 1 quality WR?
I rest my case.