Wow, you sure sound like an authority. But in the words of Jules Winnfield, "allow me to retort"....
Here's a guy on a Goldwing, on the Tail of the Dragon, with a car tire on the rear of his bike. He goes by the name of Yellow Wolf. If you're interested, he has multiple other videos of himself riding the Dragon on a darkside Goldwing, including one of him chasing down a couple of Ducatis. In spite of the many guys on line who feel like they are frustrated bike racing champions who just never caught a break, I'd venture to say that this guy on a 1000 plus pound bike with a "poor handling" car tire could out ride a whole lot of guys on S-10s with P4s.
But, therein lies the trouble with blanket statements...they're so much fun to make, but they're rarely accurate.
https://www.youtube.com/watch?v=37XLJNLpzxQ