I think it's worse to have a thousand "wow!" or "loved it" replies than to have none at all, so I post in sanctuary, and I get none at all.
Well, personally I know that I like to dig around in Sanctuary and pull up old things I may have missed. It's a very special place to put something, and because most people don't even know about Sanctuary, you better believe that you're showing your work to a very small audience. A few people might reply, and if they don't, I'm sure it's no big deal. I'm not the only person who fishes out zero-reply poems in there and responds to them a few years down the road.
Ideally I'd like to think that Sanctuary is a place for people who are less casually interested than Open, and less critically interested than Critical Analysis, but more a group of people who are interested in developing some kind of understanding of the poetry... where people who truly consider their writing to be an art, can feel accepted and understood.
Although, I don't write the rules, I just dream.