I find them a bit pointless. We're in DD's classroom all the time looking at her work, and discussing school with her, but we go anyway because she likes to show n tell smile I don't treat it as a catchup with the teacher at all, we schedule those separately.
I suppose there are parents who are not at all interested in their children's education, so it's good to force them to come in and look around once a year?
The goals the children set for themselves are pretty much spoon fed to them - DD made up her own one for the first time this year, which is great. But we never have a second conference (also that word: it's just a meeting!) later in the year to see how it all went