I use a laptop, desktop PC, phone, and 2 tablets at home. Another PC and laptop and tablet when I visit my parents. Not all of them are mine, and it is _very_ annoying to have to login to a website on them. You have to go through the unlock flow on your own device (long and complicated password) to access the password, and then copy the site-specific password (usually long and complicated) to the new device.

It is a giant pain. I can understand why people wouldn't want to go through it.