The only slightly valid argument I have seen is that it increases health care costs, a very tiny amount. Far less than cars and drivers who are less able to avoid collisions in the first place and drive everywhere.
But looking at the fact that motorcycles can be very efficient machines, means they have been using less fuel and resources as well. I mean you can get a brand new ninja 250 (which many ecomodders are getting awesome mpg with) for like $4k, and since you are part of society, you just saved society $36,000 over a volt
