Quote Originally Posted by Jecht
Lets put it this way: ANY loss of traction is stupid and will slow you down significantly. The only reason understeer is seen as bad is because it can only hurt the line you take around a corner, unlike oversteer where you can use to tighten the line closer to the inside of the corner.
You make "hurting your line around a corner" seem like its not all that bad.

It is!

Oversteer hurts the tires (im not talking about drifting).
In a race or even a street car, a loose backend keeps you from giving power to the car. Less power means slower car.

to add.

A car with controllable oversteer typically has a very good suspension setup. A very good suspension setup can be driven to not oversteer.