I don't think it's worth the pain.

I'd rather prefer to be more flexible on the directive level. If we see good reasons to configure a directive partly (or completely) with html tags (using string attributes and `@` or `&` in the directives scope object literal), we should do that.
But the general approach and convention to have a controller to configure our directive is good and reasonable, I think.

Globals are evil, most of the time.