That only applies to the password, but the password wasn't really the concern. If you're signed in (no matter how you signed in), a modified browser has the sa

That only applies to the password, but the password wasn't really the concern. If you're signed in (no matter how you signed in), a modified browser has the same access to your account that you do with creative possibilities for abusing that. You can argue that if an app isn't trusted then there are other concerns with running it on your machine and that is true too, but some apps want to avoid being too suspect in order to maintain their installation as long as possible. Extra scrutiny in any scenario like this is good. :)