OK, you asked. Nornally I don't preach because personal freedom allows you to wear whatever makes you happy, but here is what the students in my MSF class hear when they ask the same question.
"Imagine if you will, two motorcycle riders traveling down the road at 70 miles per hour. A typical speed for many freeways and open country roads.
One rider is wearing leather chaps (no ass protection), a leather vest, gloves with the fingers cut off, and a doo rag.
The other rider is wearing full protection including a full face helmet.
The both go down. You pick the cause. There are endless possibilities that could cause a rider to go down. Now, keep in mind that when you slide, you are either face up sliding on your ass and back, or face down sliding on your chin, hands, crotch, and knees.
At 70 miles an hour denim tuns to dust in a couple of seconds. Your slide will go on for several seconds. During that several seconds after the denim on rider number one's ass is gone, he is sliding on his bare ass and shoulder blades and also the back of his head if he can not hold it off the pavement. If he is sliding face down the skin on his chin is gone real quick, also his fingers, and crotch.
Rider number two, if he is lucky and does not hit something while he is sliding, can slide either face up or face down and will eventually stop sliding. When the shakes stop he can get out his cell phone, call a tow truck and his insurance company and start the painful precess of buying another bike.
Rider number one is being loaded into an ambulance and after arriving at a hospital can start the painful process of skin grafting and reconstructive surgery. His bike is the least of his problems at this point. "
It's your ass. Wear whatever makes you happy.