Starting a business is a risk, and if you have the capital to do so, and are willing to take the risk when you see a potential profit to be made, it can be only made when you take the risk. The risk is inherent to any business. You might fail. You might not make any money. But if you hire good pilots and have functioning flying machines, and you offer a competitive price, why wouldn't I fly with you?

Because there is a very small % chance that your craft might malfunction and everyone would die on the plane would die? That is the inherent risk of air travel. There is no amount of money that can bring me back from the dead - when I buy my plane ticket, that risk is calculated. I am trading my money, for the chance of safe travel by airplane, not the guarantee that there will be safe travel by airplane. You cannot perfect the possibilities. There is always the possibility of error and accident. The risk is inherent in the action.

Speaking of risk: If you had the means to start an airline business in an unsubsidized market and you say "can't" - you're really saying "I'm not willing to take the risk".