Is he an airline pilot? Maybe he copied some procedures: no trim until gear up (the reason would be to prevent trim runaway with the gear hanging out on jets).
But still, I hate it if the aircraft is nose heavy in the climb and it requires forces to keep the nose up... trim it. Even on landing, on some Pipers (Archer/Seneca), we give 2 "bursts" up short final, while maintaining some forward pressure to keep it's attitude, then releasing it in the flare, which makes it a lot easier to land (especially on the Seneca this is really helpfull).