Twitter has been similar because their landing page has been useless (when not logged in) and no search box. Usually I hear about a tweet I want to see for myself. I'll go to twitter.com, then leave and go to Google to search for it. Looking now twitter.com has changed dramatically and now has a search box.
I, like most people, are lurkers and consumers. I lurked here for awhile and I lurk in a lot of communities. At some point I may sign up and contribute, but if my lurking experience is terrible I won't make it that far. I realize this isn't what companies want, and I guess I'm not the "normal" use-case because if I was they wouldn't have anybody sign up. I have a Twitter account, but don't see the value in signing in on every device for my casual use.