People will often hold the door for me when I'm entering the building on my Segway. This happens every week or two. The problem is that it's actually not any easier for me to enter or leave the building when someone is holding the door. I'm extremely used to entering and leaving buildings either on my Segway or having it follow alongside me—it's actually quite easy and not cumbersome. By holding the door for me, you're just throwing me off my normal routine, making things considerably more difficult. Now I have to pay attention to you, make sure I don't bump into you, and figure out how likely it is that you are going to let the door slip a little and hit my tires and confuse me even more.
It's not that I don't appreciate it. It's awfully nice of you. But really, unless I'm trying to carry something, it's not actually helping, so don't feel obligated to do it.
This has made me wonder whether I should hold the door for handicapped people. I assume that most people in wheelchairs have generally been handicapped for quite some time and have gotten used to it by now. Is it actually easier for other people to hold doors, or do they also just sigh and graciously accept the courtesy, not willing to look like an ungrateful jerk? Now, I imagine that someone who is genuinely handicapped is in a somewhat different situation than someone who rides a robotic self-balancing slave for recreation and eccentricity, so I don't know if my experiences transfer or not. But it's enough to make me consider not holding the door for handicapped people in the future. Maybe I'll just ask the person if it was actually helpful next time it comes up, if I can find a way to word it so it doesn't sound like I'm rubbing in the fact that I have working legs and yet still choose to ride a personal wheeled device around.