I did bother to look; I do care; but I found the tool to be unusable. One accidental share with the wrong people is enough to dissuade me from ever trying again.
It is often asserted that users don't care about the privacy of their communications. I don't know what rock these people are living under, but it seems pretty damn essential to human existence to me. If you've run a different service where people didn't seem to care, it might be because in order to do more private sharing, they simply created a separate account. In this new era of "real name" social networks where it's harder to have multiple accounts, custom privacy settings are even more essential.
And it's simply false that it's too complex for users. Flickr does this, with prefab and nonce user group sharing, and it works pretty well. Well enough that swingers trading naughty pictures can coexist with holiday snaps.
LiveJournal had features like this since 2002 and nearly every frequent user had custom friend groups. Enough for terabytes of teen angst to be shielded from the whole school learning about it.
I think customizing sharing is a matter of getting the UI right; there's no lack of demand for this feature. Google+ takes it one step beyond, and makes it fun to sort people into circles. Furthermore they have a help/tip system that gradually teaches you how to use it. I feel sure that their implementation will be a success, and that people will be making at least as many private/restricted sharing posts as public.