Because there's no automated system, (and I guess, since there's not lots of requests, no need for it)
And so for you to want to utilise a finite resource (moderation time) for something that should benefit you, you better have a good reason for it?
Why should companies go above and beyond to comply with laws that don't affect their country or business doings?
The only reason a US company might comply with EU directives, is if they plan to do business in the EU, not if they're storing data or not from an European citizen