You're an expert on ergonomics?
My comment stands. There's nothing particularly wrong with the size of the device. I have no strain using it whatsoever and plenty of people here share that experience.
Actually, somewhat. But you can just do some research if you're interested.
Like I said, it's not unique to this device. Just because you don't feel it immediately doesn't mean it isn't harmful long-term. That's the nature of it, unfortunately.
There are things you can do to reduce it, though. Ultimately, frequent breaks and stretching are always a good thing.