[Jotalea]

alright, i'll take your point and say that Google is not a viable SSO provider. now what?

sure i could buy a custom domain and host an email server on it, but now i have to care about server maintenance, SSL, and paying yearly for the domain. but that doesn't mean i get to keep it forever! just as Google can, the hosting provider can block my account, or even go down itself. then what? i'd be in the same situation where i'm locked out.

or suppose i don't have money to pay for the domain (which is a rare possibility, but it is not impossible). now someone buys my domain, and registers an email with the same address as mine. now what? i'm screwed!

i agree that having only one centralized login method for all of one's accounts is bad, but this article doesn't provide a safe alternative.