http://store.steampowered.com/hwsurvey/videocard/
That is pretty damning on the amount of users with a 970/780ti/980/980ti/titan x. My 560ti plays most games at a decent resolution in mid-settings at 144hz. It is hard to validate a $400 replacement for non-time consuming entertainment.
Note: a 970 is in the top 6 -- http://www.videocardbenchmark.net/high_end_gpus.html