Heck, Blues Brothers was rated R and only because it had quite a few F exclamations in it…
I completely agree with what you guys say. Worst of all, if GB was too adult for kids to come to the theatre, what would the chances of RGB ever being made (oh no!).
I'll rephrase the original question, everything else aside (target audiences, money to be made, possiblity of cartoon series…), could GB have been as good or even better if the ‘horror movie factor’ was turned up quite a few notches? I'd have to say it certainly could have been as good. I wouldn't want it to go into the likes of Ray's ghost (I don't like that scene as it is, I find it stupid), but maybe some more vulgar language, scarier ghosts, the occasional victim to the supernatural… I believe Ghostbusters would do very well as a darker movie.