and you don't balance propellers either

It's really not an argument. It's a simple fact that there is no maintenance required for the valves on our 2-cycle model airplane motors. None. Ever.

The valves on a 4-cycle can require adjusting. Some will do it. Some won't. It's not exactly a winning argument that it doesn't ever need to be done because some people don't or haven't ever. My nextdoor neighbor doesn't paint his house.

We should add to the list of differences between a 2c and 4c engine is that there is PASSIONATE, sometimes blind bias for each type.