Some of the worst captains in all cultures are over 60 years old.. And put 2 old captains flying together, well that is often not good. Ask any commercial pilot.
Furthermore operating an old Junkers at high altitudes in the high mountains, fully loaded, is not intelligent. It is risky. Given that one must assume a failure at critical circumstances, be it power plant or even flying controls.
The CH folk do not have the best safety record either, be they pilots or ATC. There appears to be some complacency here, sadly unfounded.