People think it's easy since they believe that you just march around and play on this little instrument. But it's not. It's actually really hard. It takes hours for everyone to not only play correctly, but also to march at the same speed, etc.
My friend is in one, he told me how to march. I thought its when you raise and stomp your legs. But you have to roll and curve every step you take. I have foot aches ever time I try, but I think people think its because of the way you walk.
If it was easy, everyone would do it. But walking and playing an instrument, staying in line and executing exact movements, playing with musicianship, great posture and enthusiasm, is a physical discipline that requires practice, drills and repetition. Having been in marching band in high school and at UCLA, as well as basketball in high school, there are similarities in approach to the discipline.
Who thinks it is easy?? I've never been in one but doubt it is easy. Playing an instrument while walking or performing patterns in a field show does not look easy. I can't play an instrument or even read music. And I know I would end up falling, a lot, if I were to try walking while trying to play music.