Well, fwiw, these quizzes weren't even on a separate website where you need to login using OAuth, but they were part of Facebook's "apps" ecosystem. And they were popular, so everyone was doing it, however harmful (and as has been said, even if you're not doing it, if your friend is doing it, the app can also see your information as your friend's connection). Add to that the tragic permission scheme where Facebook does say "This app can see this information..." without offering an option to allow/deny sharing of some things (I think they've changed it so you can give granular permissions).

Granular permissions are also a pain point for me on Android phones. They were possible with apps on BlackBerry phones in the late 200x's, but on Androids before version 5 or 6? No, it's either give the app permission for all of requested functionality, or don't install it...