I dunno. I'm always wondering how much of becoming a more popular band has to do with some sort of formula, vs skill, timing, or even just luck.
Take the Pixies for example, there's an example of a skilled band who had an original formula that appealed to a wide audience, yet they never hit it big back in the day. Maybe it was just timing considering how popular they seem to be today.
My point is, there's many variables to why a band "makes it big" and in many cases I think accessibility is not necessarily the highest priority on the list.