Fundamentalist chr*stians and those from a Fundamentalist chr*stian background (including yours truly) don't really see an absolute non-missionary position as the "moral high ground." The world is full of people who are starving for Truth and the only people who aren't in there giving it to them is the one people who has it. Also an absolutist non-missionary position (tee-hee--"missionary position!"--snigger, snigger) implies that there is no One Universal Truth that applies to all. I very much understand that Jews have never been charged of making the human race Jewish but that does not mean they are not charged with teaching the Truth to all mankind.
Plus do you know how confusing it is to be told that your religion is just fine and dandy by someone who would rather die than convert to it? That doesn't make any sense.
I plan be`ezrat HaShem to write an essay on proselytization (and the sore point it constitutes in Jewish/chr*stian relations) in the near future at my web site.
I suppose I meant the higher ground in the sense that Jews have not used force to create converts to their religion.
I think that you don't understand this aspect of Judaism. We are the "Chosen People," but not in any elitist sort of way - it is a mission statement, since we were chosen by G-d to show the rest of humanity the right way to do things. Judaism isn't, however, exclusive. A person can be rewarded in the afterlife without being Jewish, simply by obeying the 7 Noahide laws - if they chose to worship G-d differently, that is fine by G-d, since He just wants humanity as a whole to be more moral in practice than it is (or has ever been). Jews have more obligations than that, which is part of the burden of being chosen. We are supposed to be teachers by example. Conversion of others is actually supposed to be difficult - they have to really want to become Jews.