Survival on a motorcycle is largely a mental exercise, and requires more thought and focus than driving a car around.
It is true that some people should not drive motorcycles as they are incapable of sustaining this mental performance level.
This does not mean that those that CAN achieve this level of mental capacity need be prevented from the activity, simply because certain other individuals lack the ability.
You can cut, maim and even kill yourself with a knife. Does this mean all individuals be prevented use of all knives? The possibility does not equate to the certainty, as skill and judgment temper the outcome of the combination.
You MUST drive a motorcycle like YOUR life depends on it, because most car drivers don't drive like someone else's life depends on their concern or ability. They would rather be forgiven a transgression, than provide extra thought and effort for prevention.
The rule is: "All vehicle drivers will do the worst thing at the worst time, for your maximum personal injury." While not strictly true, it takes care of the 1% of the driving population that IS trying to kill you, and the 50% that simply don't care.
There are certainly risks driving motorcycles. However, it is a manageable risk. Risk management is what life is all about and the way to extract maximum value out of life's duration.
There is nothing in this world that is perfectly safe. Water can kill you. But, try living without it!
We all take risks everyday of our lives, sometimes without even being aware of it. Awareness is key to successful management, skill and judgement can be acquired with practice and thought. Some call it an aspect of growing as we age.
I feel it is a shame to take the "thinking" out of the human designation of "thinking animal".
So, when they say "your gonna kill yourself on that thing", you must be able to respond with: "I think I can handle it. Why do you think I'm incapable and deficient with ability?" Listen. If it's about your own behavior, they could be right! An attitude adjustment just might be in order to prove them wrong and ensure your well being. If it's about their own fears, lack of understanding or lack of abilities, it's their problem. You'll have to decide for yourself if it is worth helping them overcome their problem. Recognition is but the first step, though. If you want them in your life, then "include" them in your thought process, activities, and learning experience. When they know what you do, they will understand. If not, beware of "control" or "mental manipulation" issues. If these are underlying, it may never get resolved to either or both parties satisfaction.
Cheers,