I can't help but feel that this is of equivalent or better security for users on sites that allow password-reset-by-email.
Premise: I just bought a Shield so I could start using Netflix on my TV (they still don't have an installable application for my old HTPC).
On topic: I generate all my passwords (variable length 30+ characters), and to log into both the Shield and (as a family account) my wife's phone, I had to type (or copy/send) the entire password in using a directional remote or a phone keyboard. No magic email link, no netflix.com/auth request, no PIN number, no personal wife account that I could include into my family plan.
Passwordless solutions can't come soon enough. the email route is fine for me, though I'm sure there could be better solutions too.
Netflix is one of the few things I've seen that supports google's Smart Lock for signing in. If I'm signed into the same account on my Shield as I use on my laptop, the signin is automatic for me.
Edit: changed a word for clarity.