I'm still rather disappointed in Mozilla's handling of the issue. I've since gone back to using Chrome, and away from thunderbird as well. Free speech is important to me; more important even than using and supporting open source software, which is pretty important to me. Someone's personal life, and their professional life, should be able to be kept separate, and the fact that they dragged out his political support of Proposition 8 into his professional life is a clear violation of free speech. If the issue were so important, why did they choose him as CEO in the first place? Instead, they created an obvious and blatant attack against his character for his own beliefs which had absolutely nothing to do with his day to day work, particularly given that he was a great leader, technologist, and could have brought Mozilla to the next step technologically.
Would I support a member of the KKK, or any other known "hate" group? It is their right of speech, and they are still free to have it, so long as it is not in a manner of defamation (such as slander, or libel), which looks much more like how Mozilla responded.