It would be so easy for nteflix to create a category of subtitled shows and videos. Just like they have a category for comedies, drama, instant Queue, etc... All they have to do is add them to that "list" as they are added.
Another option would be to put an image in the description of the video that means it's subtitled. Then a search in the site for that image would bring up all the pages that contain that images. Tada, a subtitle search is born for them.
They're just lazy. In fact I'm canceling my subscription until they get this fixed, more videos with subtitles and the ability to watch them with subs on mobile devices. All they need to do this is available and very easy. They just have to get off their butts and do it.
Ron Jaxon