Personal opinion but I think keeping hands on the throttles during the climb up to 3000 feet without the auto throttle selected on and engaged is positively dangerous.
Hit a lump of turbulence and the nose goes up, the speed drops off, inadvertent movement of the arm and the throttles close, next thing you know you are in stick-shake territory. At least in descent the attitude is on your side and you are possibly making minor adjustments all the time anyway.