That's a very good thought. We struggled with that during the development of -hitch-has() and a few others. Ultimately we landed on the position of getting an implementation out there that was functionally equivalent.

CSS Selectors 4 (http://www.w3.org/TR/2011/WD-selectors4-20110929/#subject) points out a syntax that is currently using "$". But that has also been suggested as "!" in the past. It's a tough thing to get nailed down, but we decided we'd rather not wait to have the functionality.