Just........
Something for your passengers to stand on while embarking and dis-embarking
Something to hide the flat spot/damage/etc to your tire(s)
Something to add to the time necessary to change brakes or tires {you do rotate your tires every 100 hrs don't you?}
Something to crack and break, needing repair
Something to discourage you from checking or adding air to your tires, contributing to a short tire life
Something to pack up with grass or dirt on a soft field
Something to add to your nose gear shimmy problem
I just cannot really think of a good reason for having them.
Charles