[jol]

technically - yes, it frees me from being part of (google/fb/twitter... whatever network is trendy now) and still sign in, practically,at the present moment, no - only geeks know about it

Edit/update: if compromised, you loose all linked accounts, however, with google/fb/.... it is the same, but this is less leaky to 3rd party, if this comes as default login, then we would have only a dozen of logins (persona/email, + important accounts, e.g. banking something similar... ), not ~100 of them, thus resetting 100 passwords is just 1 action