Yes, there are a lot of possibilities. Fit is another one - if you're putting excessive weight on your hands, it could be difficult for you to smoothly shift your weight back onto your butt.

Whether or not you ever achieve (or decide you want to achieve) riding with no hands, you definitely need to be able to let go with one hand so you can drink water, signal for turns, stops and obstacles, etc.

LAB's skills course comes highly recommended - I haven't taken it, but one of these days I'll devote the time. I wish it weren't twice as long as the motorcycle skills course... it makes it hard to find the time.