I know what you are saying. It's funny, just prior to the syncretic influx, we had almost talked ourselves into an invite system. I recall that in the wee hours while driving to launch that snail in a weather balloon, we were talking about the merits of it. I was inspired by lobste.rs invitation tree approach. It would be interesting if rather than just earning badges as your hubwheel turned, you earned invites. I think that ideally, rather than an aggressive front end filter, we have a situation where the right people stick around, and the wrong people don't. I think that we have been fairly successful there, but it's the slow creep that we all worry about.
Designer news has it set up that you can only sign up between noon and 1pm every day. This makes it so the people who really want to join can join without jumping through invite hoops while still keeping out those who want to make a one off comment or spam.
No it's 12-1 EST. It took me like 5 days to remember to do it when I got to work. Kind of annoying but I'm sure it helps.