First you refuse to admit ghosts into your mindset or world view, then you blame them for living in old, abandoned dumps. Because it makes for a more entertaining story - not a truer story or a more logical story. Life's a pain in the ass. Hanging up on telemarketers who call during dinner is just one of them. If ghosts walk the earth because they died horribly and unjustly and seek revenge, then those who died the most horribly and unjustly ought to comprise the majority of ghosts we hear about.
People learn by doing.
If supernatural forces always stepped in and did our job us, we'd never learn anything and end up perpetual children. Those that remain have survived by being better adapted to conditions on this planet. Unfortunately for you ghost believers, the hard reality is life is for the living - period. Well, this first attempt to exorcise the ghostism from my life doesn't seem to have worked quite as well as my previous attempts to rid myself of my racism and sexism. I'm still cringing inside when I imagine my daughter calling me up to tell me that she has just been impregnated by a fellow who happens to be dead.