So if the throttle friction is loose on a full power climb-out the engine just winds down because there is no hand on the power lever? Saving some asymmetric wear on the control column could cost lives.
To clarify only during rotating and flaring. Apart from that the hand is always on the throttle.
Regarding the asymmetric thing:
Its not about wearing out the yoke. But the fact that the yoke might get stuck or not move smoothly if you pull it on one side only. There is some logic to that in my opinion, since in small airplanes the yoke and metal stick is all mechanic. During rotation and flaring the pull is relatively pronounced and there is a long movement forward or backwards. I was told this could occur on older more worn out planes.