Sometimes, the smaller roles in movies can be the most interesting. If you only take the stance that you'll only play central characters in movies, you'll find yourself not being able to indulge in that morally grey terrain that makes support characters so rich and interesting.
Traditional matter must be glorified, since it would be easier to listen to the re-creation of familiar stories than to quite new and unexpected things; the listeners, we must remember, needed poetry chiefly as the re-creation of tired hours.