This has been going on for years at a customer's house. Mom and Dad and three boys, now eight to eleven years of age. I have replaced at least forty broken switches so far at this house. The rate of breakage has been slowing down over the years, possibly because the kids are maturing.
Dad has been watching the kids operate the switches and has not noticed anything unusual. Not bouncing balls off the switches or using the end of a hockey stick to operate the switches. The receptacles, located further down the wall, do not have this damage.
I have been replacing with spec grade switches and that has definitely helped. The ones breaking now are the old ones, not the spec grade.
Any guesses as to cause of damage?