If someone is complaining about your service, it may be a good idea to listen to them. All of the "Blah, blah, if you want it you should be able to create your own super successful site" posts are really rather pointless. Yes, site/company owners have to make some tough decisions about their product, and how users can access/use it. There are going to be complaints, and there are going to be users who disagree. Telling your users to "shut the fuck up" when they're saying they disagree when you've gone from supporting them to destroying what they've built without telling them anything about it seems to be rather harsh.

Its easy to come out and say "Oh, he can do anything he wants because its his company, and if you don't like it just leave". It takes a hell of a lot more effort to actually put the finger on why a move like this (blocking an entire site which hosts various mashups, over 2000 targeting just Craigslist, without notifying the users or having any real method of notifying the "developers" why it was done, or what they can do about it) and trying to point out to the people who actually could do something about it.

As a tip, if you're getting that much flak from your users that you have to start flaming users on the internet about it, you're probably doing something wrong.