I don't think people cared all that much about whether or not the content was citable. You can't cite Wikipedia, and that's not going anywhere.
replyFacebook may well fail when people don't enjoy it. But all Google ever promised was information, of variously dubious quality, and that's still their draw.
Fair, citable is probably the wrong term.
replyThis is a problem Google has been battling forever, with all the SEO click spam.
In either case, Google was the tool that many people used to find "trustworthy" information (citable or not), compared to the other tools online.