What's stopping them? Bashing would not be legitimate in a normal room, but it clearly is in a dirty room. There is no real difference between clean and dirty, just a different set a rules. Same thing as NASCAR vs F1.
Why would you cut out the first part of that sentence which makes the second part you did quote make sense? I was clearly referencing REAL banger racing there. You can't just t-bone and drive recklessly in that sport so i'm not sure which laws or rules dirty racing lobbies are conforming to?
As I said i'm not stopping them doing what the like, I was merely replying to the point about it being a legitimate way of racing.