Surely we've gone off the deep end if we're pretending that a 1070 is a mid-range card. Video cards are already an enthusiast class product--the mid tier of PC gaming is integrated graphics or one of those crappy nVidia mobile GPUs. The modal Steam user has 1GB of vram. The median PC gamer plays LoL, WoW, and Minecraft. People playing new release AAA games at 1440p or 4K or buying VR are like 5 standard deviations right of the mean.
But even among the dedicated GPU people, a 970 is beyond enthusiast overkill. Someone can get good, >console performance at 1080p with good effects (and for everything other than new-release AAA, do ultra and super-sampling) on a 780TI or a 970. A 960 is great. A 980 is beyond overkill. A Titan is beyond beyond overkill. And the 1070 is outperforming a Titan on some benchmarks and we're complaining that nVidia isn't offering enough mid-tier value because they're selling a reference card?
It looks like on Steam right now, running a 970 would put you in the top ~8% of gamers on Steam. So we're already self-selecting for people hardcore enough to PC game, to have a Steam account, etc. The biggest grower in the last month was the GeForce 750 TI--and after that the 730, the 960, and the 750. I'm on a 770 (someone else's used handmedown) and I get great performance at 1080p.