I would say it's not really the death of personal skills but the teacher should be there for his students, paying attention to them and not just glorying in what he has to offer them. That means you have to work out on your own time. Class time belongs to the students.
As previously pointed out, you do learn more and soving problems for others can clarify your thinking about your own training.
Eventually you may find students good enough to be training partners. That's when you set aside time not for teaching, but for mutual learning. It pays off in the end.
"Look, I'm only doing me job. I have to show you how to defend yourself against fresh fruit."
For it breeds great perfection, if the practise be harder then the use. Sir Francis Bacon
the world has a surplus of self centered sh1twh0res, so anyone who extends compassion to a stranger with sincerity is alright in my book. also people who fondle road kill. those guys is ok too. GunnedDownAtrocity