Perhaps a better survey would be the one by Firefox[0] since it isn't biased towards gamers. Basically HiDPI monitors are like a combined 2% of all Firefox users.
1080p usage is lower than on Steam but that is because 768p usage is higher :-P.
Just like programmers should have to run their apps on 10 year old computers and feel the pain, so should designers have to try their work on 10 year old monitors.
That isn't going to be the case for Apple users though is it. Apple don't have any non retina devices in their lineup now. The only Apple users who will see a low dpi display are those plugging in a low dpi external monitor. They are going to be a minority.
I guess that is the reason why every musician should copy their master to a cassette tape and go to a shitty car with a tape-player and listen there, why every developer should have a very old crap-computer to run their software on and why every UX designer should have a crappy screen to view their design on. :-)
The devs and designers are all using 4k, 5k displays these days. Trying to use modern apps etc. on just "FHD" (1080p) displays is painful.