There are, that is true. But the number is small in comparison to the number of people not doing enough even though they are going to the gym or exercising regularly else where.
Recovery is the most important part of any strenuous activity.
I’m not sure what you mean by ‘overtrained.’ I definitely see people who work out harder than they need to. The risks outweigh the benefits. Often posture and technique are the victims. Speak with the client, but don’t expect immediate response, or even down the road.
Exercise can be very addicting; sometimes I over train my self because my body feels restless. I am working on moving from one to two rest days per week so that I can be sure I get enough.