Bitcoin XT is basically a new bitcoin that is profitable for Coinbase. No one supported it from the beginning. No one will in the future. The original is the one and only, and no fake can best it. Bitcoin XT was never going to be a success, anyway.
I suspect XT has achieved exactly the effect "they" intended it to. I don't believe the real force behind the XT push ever intended or believed it would gain adoption.
Beat the price of BTC down, FUD and "divide & conquer", mission accomplished.