Well, on a very simplistic level, the drivers are the ones with a steering wheel and control over where they put the car on the circuit, aren't they.....?
I'm going out this morning down to the shops, I could drive over the curbs here and there and drive over the pavement in places to get me past traffic and potentially get me there fractionally quicker, but I don't, as that would be foolish and it's not allowed as I am supposed to drive on the road. I know that. So do all the other drivers. The fact that the pavement might look inviting to me or give me some advantage due to the design of the road is neither here nor there.