i say it can be & should be both depending on how it is built.
if it is made to do 20mph, it is a bike.
if it is made up to higher standards with lights & signals & over 20mph.
it fits the legal definition of a moped.
i saw a post in the main forum about using moto/bikes for disaster recovery. it is a good idea to use that as a "card" in the hand.
i lived in south florida. about 5 years ago we had huricanes knock out the power 3-4 years straight. once for over a week.
it took hours to find & wait for gas. i didn't have a problem though since i have scooters that get almost 70mpg.
our bikes get somewhere between 100-120mpg.
also many cities are having problems getting people to spend money localy. like down town. (at least ours is.)
being able to scoot around on a bike, moped, or scooter helps that.
in addition it helps traffic.
all the locals in south beach drive scooters & bikes around.
it is the only way to get around while bypassing traffic.