The purpose of the spoke protector is to keep the chain from getting shifted off of the largest cog into the spokes. A properly adjusted dérailleur won't derail the chain into the spokes -- hence the name "dork disk," because presumably dorks don't have properly adjusted dérailleurs.
I'm pretty sure 13 year old boys don't worry too much about the adjustment of their dérailleurs either, in spite of the best efforts of their fathers. I know first hand the damage that can occur when a chain gets shifted into the rear wheel. The damage can easily run into hundreds of dollars.
What do you think? Should I hope and pray my son will always keep his bike well maintained? Or should I prepare for the worst and assume Little Fritz will be about as consistent on his bike maintenance as any other 13 year old?
Should the dork disk stay or should it go?