There are a few places where `selector` are jQuery element and some not IIRC and I get confused sometime.
It might be true that **you** know that element is alway jQuery but not external contributor. 
I think it is a nice way to state what should and should not be jquery enabled. 
if it has a $ it is jquery enabled, if it is not, it is a bug. like underscore mean private. 

I'm find with removing it if you insist, but having taught javascript basic to a friend durring christmas I think it would 
be a good to move to prefixed with $ when possible/relevant.