Registered '07 SLK55
...makes me want to swap 125 tires onto the SLK!
I think his point wasn't so much that massive oversteer with skinny tires is better on the street, but more about how most manufacturers these days are so concerned about track performance and lap times that the cars become so perfect that at street speeds, they have too much mechanical grip and too well balanced to have a little fun before breaking the speed limit.
Cars like the C63, with "narrow" tires in comparison to their torque and horsepower numbers, allow some fun without having to break the speed limit or get too dangerous.
The point is: Certain cars can have brilliant performance on the track, put down amazingly quick lap times... but in the end, are they fun to drive? Maybe imperfection can be more fun than perfection.
Example: Nissan GT-R. Absolutely phenomenal performance on a track, but reportedly quite boring on the every day drive.