I don't see what art, healing, sunlight, etc have to do with not being straight so whats the point, i mean straight people dont have a flag, why would others require one
it's about empowerment.
gay people weren't exactly treated super great in the old days, so they banded together in cities like san francisco for support. the flag isn't about gayness, it's about gay pride. the reason why art and spirit and etc. are all on the flag is because they want to show that homoloveuality is positive and normal.
straight people could easily have a straight pride flag but there was never anyone getting ostracized for being straight, so there never really was need for one