There is another difference between twitter and facebook.
The twitter opt-out was for one feature and only on that one site.
Facebook doesn't provide a way to completely opt out of this feature.
Note #4 on the list 'Finally, check Facebook’s “Help Center” frequently to see an up-to-date list of applications that need to be individually blocked to maintain your privacy'
Facebook takes the action of automatically adding you to new sites, but not telling you that they have done this. So the onus is on you to continually go back and remove these sites from your feed.
Furthermore, Facebook is continuing to share your information with these sites, all you are turning off is your view of what is being shared.
The twitter opt-out was for one feature and only on that one site.
Facebook doesn't provide a way to completely opt out of this feature.
Note #4 on the list 'Finally, check Facebook’s “Help Center” frequently to see an up-to-date list of applications that need to be individually blocked to maintain your privacy'
Facebook takes the action of automatically adding you to new sites, but not telling you that they have done this. So the onus is on you to continually go back and remove these sites from your feed.
Furthermore, Facebook is continuing to share your information with these sites, all you are turning off is your view of what is being shared.
It's very shady.