Some instruments are harder than others in the beginning. They all seem to meet up somewhere at the end of the road and become just as hard to master though. Its also an indvidual thing, some people are to clunky for a guitar and others just dont have that inner groove that drummer needs. Its a great thing that everyone is drawn to their own instrument.
I play percussion but was originally a guitarist and mandolin player. They are all just as hard as each other in the end.