I've been riding since I was 7, I'm currently 44, I've lost friends to motorcycle accidents, and walked away from a few myself.
Motorcycles are inherently dangerous, but can be driven safely, wear the proper gear, pay attention to everyone around you and drive like everyone is out to kill you.
Riding take practice and skill, I see kids, 17 years old riding motorcycles that are able to reach speeds in excess of 160 MPH, these bikes are designed to race on a closed course where there are no telephone poles, railroad tracks, pot holes or cage drivers on the same road.
People die in planes, cars, boats, motorcycles and walking across the street, so in answer to you question, motorcycles in and of themselves are not dangerous, it's the people on and around them that can be.
On a final note I have a friend who had ridden nearly as long as I have, he's traveled by bike cross country 4 times, in all that time he's walked away from 12 accidents.
He finally gave up riding 2 years ago, I asked him, "What took you so long?", he said,"13 is my unlucky number so I quit before it was too late."