Is motorcycle dangerous

yes, and i can think of 4 reasons:

EXHIBIT A: you have very little protection in a crash
EXHIBIT B: most dont have a spedometer, and you can rear-end a car
EXHIBIT C: they have less traction for brakes, so rear-ending cars is more common
EXHIBIT D: they...alter the mind. most people say they are "(dumb) king of the road and believe they always have the rightaway at intersections.