Why wouldn't you want an exception to be thrown if a null component is being injected or outjected?
I think the default behavior protects the user from a NPE unless they explictly override it. It Helped me quite a bit as I was just starting with the framework. As I've gotten more comfortable I have seen places where I can safely turn off the requirement but it's definitely a smaller percentage of my bijections that have a required=false
In fact i dont have many points that needs required=false, but it still looks that it should be default for me. I dunno.
Anyway, thks for the opinion. :)