I just did a similar look back into tracking, and I think I see why he was defensive. These numbers may not be statistically relevant, but it is an example of what the car can do under normal driving. Anyone who may be shopping for this car and comes here can look at his sheet (or what I wrote) and say, "Ok, this is the mileage I want to get and should be looking for in my purchase" and have a reference. Which is nice and interesting, and most people don't even bother to track that thoroughly.
Also it could be that he just spent the last year tracking his mileage, spent the time to post it, and in 4 paragraphs you kinda just shrug it off.
I'm just trying to explain why I think he reacted as he did. Your points are valid not saying they aren't, but I don't think he was going for the super scientific approach.
Correct me if I am wrong.