The Google spider has an entirely different experience, when going from page to page on Quora, than what the user does (someone not signed in).
Google hammers any normal site that gets caught presenting a fundamentally different experience to the user than they do the spider. Google is not unaware that Quora, Pinterest and LinkedIn present different experiences to the bot vs the user, they knowingly allow it for giant services. That's the hypocrisy and double standard.