I think you hit upon the key to the "Lovecraft obsession." We all have a "little lovecraft in us," (that would be a great tee-shirt!). We all have an "Other" that we fear and "otherize." It may not be a race or ethnicity or gender, like is easy to see and malign (whether rightfully or not) in folks such as HP. It may be an ideological orientation or political affiliation or other identity that we find disconcerting, or simply the folks that we don't like, for whatever reason.
I think that is why his influence is so profound: he palpable depicts in his work--and evidently through his very personhood--an aspect of ourselves that, while hopefully most/all of us in this thread don't embody to a degree comparable to him, we all still have. We all have our own version of the "Other," but sometimes it is less easy to designate what it is for ourself. I think sometimes, the Other are those who we see as worse about othering than we are!