Profits look to be extremely low right now. Not profitable at all with the current cards. Sucks.
Now it`s normal. 1080ti is a really powerful GPU but if you count with price/profitability - 1060(3) much better then 1080ti. If you have enough free space of course.I guess it would be a faster ROI because of the price of 1060 TI's but like you said, you'd need a hell of a lot of room to set up 24 1060's and that power draw would be a beast.
It's not only that, you must also calculate expense that rise with additional cables, risers, PSUs, mbo and all stuff you need if you cannot hookup all cards to one rig, and you usually cannot.
ROI cannot be calculated just from GPU perspective because it gives you false results.
There are motherboards that can take 20+ GPUs if you're planning on it, but like you said, you would need some serious infrastructure to handle 24 1060's, the energy problem alone would need some electrician assistance and the heat, etc.. I'd rather stick with the 1080 ti's (and I have)..
