If you care about your online presence, you must own it. I do, and that’s why my email address has always been at my own domain, not the domain of any employer or webmail service.
You might think your
@gmail.comaddress will be fine indefinitely, but if I used a webmail address from the best webmail provider at the time I broke away from my university address and formed my own identity, it would have ended in
@hotmail.com. And that wasn’t very long ago.
Locking your identity in won’t prevent a major social service from succeeding. Sadly, most people don’t care about giving control of their online identity to current or future advertising companies.