There may be any number of reasons.
One may be that they want the security of being able to identify you.
I suppose it does create a degree of risk.
The reality is though that unless you comply with their requirements they cannot be compelled to provide a vehicle.
Can I clarify anything for you?
Yes, I understand.
You can make those offers.
They may agree.
But if they do not then they cannot be forced to provide a courtesy car.