SS,
Thank you so much for sharing your thoughts. Before I read your post I really didn't understand where my dad was coming from. Now I see it is probably more than blind, visceral reaction. Given your analysis of how negative opinions of BDSM are formed, it seems all the more important to "come out" to family and friends, so they know that they know and love perfectly well adjusted BDSMers.
It was also encouraging to hear how well your family reacted. I can imagine my family reacting that way, now. Of course, I can imagine other, less pleasant reactions, too.