Re: why....dont bicycle shops...
I have a good friend who owns the local bike shop I've been going to for the last 15 years.
I think one of the reasons is (at least for his shop), he is too busy with regular bike stuff most of the time.
One other thing......bikes in general aren't designed to have motors mounted to them.
That would be a huge litigation nightmare for any LBS owner.
If some's good...more is better and too much ain't enough.