Probably for the reasons I mentioned in the previous post. GDDR5x has currently no advantages for mining over the regular GDDR5 (except some very moderate power savings). The compute difference between 1070 Ti and 1080 is only about ~5% (based on the number of cuda cores). You'll lose a lot more than 5% in the algos that are memory dependent (that's ETH and Neoscrypt for the most part). ETH rarely makes sense to mine on nvidia cards, but Neoscrypt is all the rage right now. And it's faster on 1070 Ti.