Alot of Lovecraft's writings weren't exactly horrific by today's standards, but the man also lived just after the turn of the last century. Language was different, inventions we take for granted today were "sci-fi" to people back then and people were easier to take fright due to a lack of horror flicks with advanced special effects about. Make no mistake though, Lovecraft is the definitive father of the macabre and horror would not be the same without his influence. He took suspense, the supernatural, thrillers and general horror then added a twist to create some of the most original, disturbing, breathtaking and utterly, grotesquely, brilliantly dark displays of literature of his day.
Some interesting facts about him is that he barely made a cent from his works (most was through the publishing of short stories to horror and sci-fi type pop culture magazines at the time, a bit of a trend back then) and they would have remained unknown if it wasn't for his collegues publishing them after his early death - he never published one of his own books. He also predominantly corrosponded with people through letters rather than conversation. He loved to take the piss out of his peers by telling each of them a different way on how to pronounce cthulu properly, that is why there is so much confusion to date as to how it is properly pronounced. Personally I think the only person who could really tell you it's proper pronounciation is Howard Phillip Lovecraft himself. I plan to ask him once I cross the barrier to where dark things do dwell.