What about swapping out the gate with one from a '11-'13? Would be a PITA, but an option at least.
I agree that I barely use it, but like others have said, that last little bit of luggage that needs loaded up, won't go in any other way!
Also, if you have a hitch carrier rack, you likely can't open the gate with it loaded up. My co-worker found that out the hard way on his Acadia. I told him to just open the glass, and he said it doesn't open on the Acadia. I told him he shoulda bought a Jeep, lol.