True, and in fact a big budget LOTR style end movie would be a nice narrative cap to the series. He would obviously have to write it as such though.
The bigger problem is logistics though - even if all 12 million viewers of the show who regularly tune in go watch the movie (which is unlikely, ever single one I mean), that's 120 million dollars, which is about what the movie would cost anyway. Add to that a $40 million marketing budget (the avg. for a big-scale film) and any studio would be reluctant to greenlight this. I'd be there, just not sure any studio is willing.
Back to the ME talk - I call bullsht. I think the studio/writers got lazy and put it on the backburner (the movie).