"If at primary time, there is no winnable candidate that matches your point of view, it is because people do not share your point of view, and you have failed to take responsibility for making a compelling case so that they do share your point of view, or you have failed to disseminate that point of view. Your responsibility."
Oh, so you agree with me then about people having a duty to make the case for who represents them the best. That's excellent. I'm assuming that there will be at lease one candidate who represents everyone's vision, whether you are to the right (Bayh, Vilsack, Hillary) or the left(Clark, Edwards) or even in the middle (Dodd, Biden). "Winnable" doesn't enter into it. Let everyone vote for their most representative candidate, even if its someone you have decided is "unwinnable". Let the chips fall where they may. Everyone takes a risk, and then when its all over, everyone falls in line for the general.
"Punishing other Democrats for not sharing every one of your points of view by making sure that none of those points of view get carried into real elective office is unfair and irresponsible."
When someone disagrees with you, and expresses that disagreement through their primary vote, that's punishment? I thought it was democracy. Under your view, you might as well cast their vote for them, since you've apparently decided they can't handle it. Make your case on the merits of your candidate (not on hammering other candidates as "unwinnable"), and fall in line if you lose. It's the same advice I'd give to any candidate's supporter.
"I don't deny people the right to vote for whoever they want, but I also have the right to point out where it will not do them any good to exercise the right without taking responsibility to truly get what they want (or at least more of what they want)."
Sure you have that right, but I think each of us can determine how best to get what we want, without someone else like you to instruct us. It shows a profound disrespect to presume to lecture others on how they are holding back the team because they vote for whom they choose, when it isn't a choice approved by conventional wisdom. Again, it makes it sound like you think that you are more qualified than someone else to cast their vote.