And that's just the way things are these days. It is, in fact, perfectly possible to be a huge fan of the movies, TV shows, games, etc. without ever engaging with the source material--which may or may not be very different from the media adaptations.
I don't think it's just "these days." I daresay that in the 1940s, more people knew Superman from the radio show, the Fleischer cartoons, and the daily newspaper strip than they did from the original comics. That's why the comics adopted so many things from those other sources (Jimmy Olsen, Perry White, kryptonite, and eventually Inspector Henderson from radio, the Daily Planet from the newspaper strip, Superman's power of flight from the cartoons and radio show). And the Adam West show made Batman a household name beyond what the comics had ever done.