You make a good point. However the safety factor has increased tremendously. I give them a lot of credit for that.
I agree with the better safety aspect.
But the body template doesn't have to be the same.
The different body designs affect the speed and handling making for a real competition.
And fans can identify more with a car that looks like the ones on the showroom floor.
Having one body template makes it more like the old IROC races.
But making the teams pay to use the mandatory NASCAR design brings in a lot of money.