I've been on a real Boris Karloff kick lately (see my recent triple-feature review over on Horror Squad), which started with back-to-back viewings of The Black Cat ('34) and The Raven ('35). Both films were made when Karloff was the premiere name in horror, but the roles were so strikingly different from each other, that I wondered how audiences perceived him during the glory days of Universal Studios' horror films. Was his box office appeal based on him being "the creepy guy" or was it due to his versatility in a film genre that was just beginning to find its legs?
I'd argue that without Karloff's versatility, the genre would've evolved in a completely different way. With such a fantastic character actor in generally unsavory roles, Karloff elevated horror films into perfectly acceptable entertainment. There's art in Karloff's finest performances, and how can horror be all bad if it's artful? We don't have anyone like him today, and without anyone to add that touch of class to horror, the films released now are widely considered base, lowbrow entertainment.