I'm no expert on this, but he's living in a 1920s New England, not the deep south. Those views seem racist by those standards as well as by today's.

But no, it's not going to stop me reading and enjoying his work. Although I don't think I would, for example, feel comfortable running a Call of Cthulhu scenario in which the investigators fought not against shoggoths but against 'vice-ridden niggers'.