Fans and racers alike claimed Nascar was regulating too tightly, making the scope of the car too cookie cutter, too narrow of regulation, too many new rules. So they respond by opening it up a little by allowing passing under the yellow line, allow bumping, etc.
Now dickheads like Carl Edwards take it way too far. Maybe he didnt expect that result but shit if you are intending to get back at someone, save it for a short track or something.
The same reason Nascar is dominating IRL is the same reason boxing is going to disappear in the shaddow of the UFC. Its more interesting to watch.