Why do they need the web?
If the only way to watch Game of Thrones is to install a standalone application then people will simply install the standalone application.
I think this is the crux of the issue - should the web be a general purpose platform? Or do we draw a line somewhere and say some tasks, like watching protected video isn't something it should be doing. Personally I think all video consumption is a good fit for the web, it's seem awkward to split protected and unprotected video.