But investors are also entrepreneurs. As such, they expect to make their money back, at the very least, and have a megahit, at the very best. Even though financing movies is a risk, investors do not set out to throw away money. Private investors and studio moguls alike look for scripts an audience will want to see. The reasoning may be highly subjective.
Most equity investors finance pictures they want to see themselves.
If someone's hobby is karate, that is what he will like. If he used to be a policeman, he will probably favor cops and robbers. Compare your budget to the potential of box office grosses. In this sense, commercial only means that you have the potential to make more money at the theater than the cost of producing and distributing the film. Make your pitch reasonable by keeping the budget commensurate with your experience.