We don't have periods this end. We have full stops. Any rules about where they go apropos of speech marks are applied very inconsistently all over the place. To me, that means that the rules don't matter much. It's what people do that matters more. You get the same argument about things such as "irregardless" and "begging the question." What starts as misuse morphs into standard English so you might as well not quibble. Just don't come around here with your bloody "prior to" or "albeit," that's all. Grr...