For the better part of the last four years, I have managed, quite well I might add, to do without a Facebook account. Yet, despite this, more an more applications seem to be depending or relying on you having a Facebook account in order to use them. This is true of a wide range of things from comment boards to business applications. What baffles me is why anyone would tie their application to Facebook.
Sure, I get the idea that the general public is stupid when it comes to technology. They cannot remember their passwords (which is why Apple put a fingerprint scanner on the new iPhone), they cannot manage to understand what a URI is or why it matters, and basic interfaces confuse them, but Facebook is hardly the panacea, and worse, it opens the end user up to even more insecurities and potential application and privacy leakage.
So from this point forward, if your application, chat room, or comment board requires a Facebook account to use, I will give it an automatic fail and one star rating. Real application development does not rely on some other application for its security model. And the general public should not accept any application or solution that does.