Simon, I the lack of respect comes of trying to appropriate a dead Jewish person's identity as part of one's own group. "Oh yes, but she was baptized a Mormon" kind of dilutes that person's historical identity in a way that really isn't true. That said, I absolutely agree that everybody has the right to try to convince others of their own version of the truth, so if a Mormon wants to witness to a Jew, or a Christian, or... anybody, that's permitted. Just like it is for atheists, evangelicals, rationalists, pragmatists, pagans, and pantheists.