Look, I don't really feel like writing a "composed", "well-thought out" entry right now so instead I'll just say some real shit: excusing American racism, sexism, homophobia, and the like by stating that the bigots in question are a "product of their time" is, by and large, bullshit. This is not to say that one's environment shouldn't be considered at all when examining their viewpoints, but rather that environment as an explanation for attitudes and thoughts can only go so far. Environment informs the greater context within which a person interacts and draws information from, but ultimately the attitudes that emerge from those constant interactions belong to the individual. There is a difference between your average dog fighter and, say, Michael Vick, both in terms of what one deems acceptable and the degree to which one is willing to pursue what one deems acceptable.
Anyway, my point. Bigotry. Time or origin, taken alone (or with anything else, really), does not excuse bigotry because there were always people who existed at the same time-space who were not bigoted and/or actively acted in opposition to entrenched bigotry. Take Huey Newton's call for solidarity, for instance. The man clearly acknowledged his own prejudice and clearly alluded to environment as a root cause of his unease. Nonetheless, he chose to overlook and overcome his prejudices to pen an essay that, 40+ years later, is still well above the heads of most people anywhere. I can go one step further; John Brown went as far as advocating - and practicing - armed resistance against Southern slaveholders before the first shot in the Civil War was fired. For every Huey Newton or John Brown, there were thousands of folks who resisted societal prejudice on a smaller but no less significant scale throughout American history - be it an interracial couple here or a brave group of students there.
I'm not asking bigots who grew up in a different time to retroactively become the next John Brown. I'm asking you to stop excusing their intolerance, be it H.P. Lovecraft or your own grandfather.