What if you don't use Twitter, Facebook, GitHub, etc.? Do they have a way of establishing trust that does not involve signing up for various identity-harvesting social networking services? Maybe a certificate that you can host on your own web server or something?
but more types are in the works. Though proving your identity on more than just your personal website has its advantages. For one, I don't know anything about your hosting situation or your security practices.
This seems very sensible. For example, at a key-signing party, as I understand it, ideally everyone knows someone there, or can authenticate via two separate government ID. The benefit here is that keybase.io has removed "government" from the equation.