As far as discriminating between a car purchase price and repair costs, I can see the argument. Granted it does come out of the same pocket. But let's say the car has X intrinsic value (monetarily speaking). When you purchase the car for X, you are expecting to recieve X dollars worth of car. As repairs come along, the intrinsic value of the car does not change. However your total outlay of money has, to let's say X (initial purchase) + R (repair costs).
The point I think that frustrates people, is that since (X+R) is not equal to X, they feel that their value has greatly diminished, specifically by a factor or (X+R)/X. If repair costs are significant, and unexpected, the total X+R may put them into a total expenidture situation that had they initally spent (X+R)would have left them with a car in much better condition, and that would have a significantly higher intrinsic (monetary) value.
Granted repairs are a fact of life, and any car, at some point in its life will experience them. But they are frustrating, and change the financial picture for any car in a hurry,
Best wishes and take care,