What is so special about H.P. Lovecraft?

I've been reading Lovecraft's short stories for a few months now. I think it's safe to say at this point that I'm a big fan of his horror, but I can't understand why he's so revered by ordinary readers, writers, and scholars alike.

Though I admire in particular his rambly, psychological style of portraying events, I have a feeling there's more to him than that. Can anyone help me out?

He basically codified/created the "cosmic horror" genre— meaning he's the (cited) grandfather of a lot of modern day horror tropes that go along the lines of "this thing from outer space/old pagan god/unspeakable demon beyond human comprehension is going to kill us". His philosophy has its own wikipedia article.

The thing about history is, the people who made genres end up being forgotten as among the first people do do that. But, because they usually have people build upon them for a century+, their contribution to the genre looks unremarkable as a result.

He's an average storyteller. I'm still creeped out by one horror short story I read, but it's also the only piece of horror I've ever read (my at the time boyfriend loved him and I wanted to see what all the fuss was about. I was not particularly pleased with his recommendations).

But he was one of the first if not the first to really dig into the concept humans are insignificant specs of dust and using that as a terror driver in his stories. He's definitely the guy scholars accredit for starting a whole lot of tropes. Hence, he's a revered author because he brought some core horror concepts to the genre.

Thanks @Rosendorn! I walked away from this a bit more enlightened about him than before. I think I can finish his other stories off with a greater appreciation of him.

Well, I was going to answer this, but Rosendorn stole everything I was going to say. He's like Stephen King: he set up the guidelines for horror writers everywhere -- what to do, how to think.