I think that the summer heat could be causing some lack of interest, at least around here.
I haven't felt like riding my motorized bicycle anywhere. It's too slow for quick trips to the store, but great for just exploring. I just don't feel like riding slow and exploring in the high heat and humidity. I just want to get where I'm going, and back again as quickly as possible.
Maybe, when the temps cool, and the leaves are changing colors, more people will get back into motorized bicycles just to see their surroundings up close and personal.