"Most plausible explanation", hahahahahafreakingha. Yours is a completely implausible explanation. Even assuming that Mr. Tarantino (note correct spelling of name Mr. Smug) was incapable of spelling common words like "bastards", it is impossible to imagine that nobody from production assistants to studio heads was able to successfully correct his error. I realize his explanation for the misspelled title may be unsatisfactory, but that is consistent with his explanations for almost everything he does. He probably means to say "because I felt like it", but it's not at all in his nature to be succinct when talking about himself.