[andreasvc]

Yes, that would be better for the user, but this is a free service, and Google has not much too gain from making the process more complicated (imaginative) and thus more error-prone. As a user you have the responsibility of keeping your password absolutely safe, if you do that (and better yet use 2-factor auth), nothing should go wrong.

Your option 1) boils down to adding more "passwords" by which the user can authenticate itself, so it's not a fundamentally better protection as they can be guessed by an attacker as well. Requiring a text message confirmation for password changes might be a better idea.

[fauigerzigerk]

All steps on my list are either fully automated or optional, so it doesn't cost them more.

Google has a lot to gain from people entrusting them with their data, that's why they provide a free email service in the first place.

It would be a mistake to think that trust is linear. You can't just treat a few people very badly without risking a major backlash against your business model.