The problem with Google's passcodes:

1. I don't use Google account on my phone. In a rare occasion I need to access gmail outside of my home, I just log in via a browser, either on my phone or work computer or wherever.
2. My home PC has no authentication whatsoever. The three physical locks on my apartment's door is the access control. Couldn't lug it around for authentication, anyway.
3. I have no other devices that could be used for this passcode thing, and my phone is usually laying around somewhere, probably shut off with empty battery.

In fact, I have not bothered even with 2FA for google accounts. At this point these are just "garbage collection accounts" for spam and youtube subscriptions/playlists, anyway.