Well you say that but you didn't say how. I have seen some just come off in my hands and some I had to put in a press. Depends on how well it is seated on the taper.
If the motor is out of alignment then usually it is hard to turn all the time. My LS came with its second motor way out of alignment.
When the shaft is bent/bowed it will be easy then hard.
In 20+ years of owning a MC Stars and Stripes I only ever had one prop, sure it was in the shop (Marine Wheels of Panama City) a few times, but I had no less than 3 drive shafts with the same boat!
The last shaft was custom made since I could not get a factory part anymore but that was relatively easy here in this Port/Town. The problem I had was the shaft came with the flange on it and there was nothing short of a large press that would get that flange off. I was not about to pull the motor to install it.