I read a story where someone lost access to their google account and had to go through living hell to get the access back. Reaching a human for support was outright impossible.
Privacy was not that big a deal for me, but if I had lost access to my email for any reason, I would have had zero rights to demand what is mine - because nothing is really mine, as I have never paid for the service, so I was never a customer to begin with.
I moved off gmail last year after using it since 2004 (I remember getting an invite and using the service even before it was launched).