One of the reasons people have no idea what thunderstorms really look like is simply because of the lack of visibility in most places due to buildings, hills, trees, etc. Even a garden variety thunderstorm can be beautiful on the Plains, or out over the ocean, but outside of that, like where I live in the Philadelphia area, there’s often not much visibility. I also think discrete storms are relatively rare, in terms of the likelihood that residents can see one from a fixed location (i.e., as opposed to chasing); there’s not much to see with a multicellular cluster, specially when it’s right over your head.
Having said that, even when there is something cool to see, I’m amazed at how many people fail to look up at the sky. They are too busy looking down at their phones or their shoes.