Solid-Stark on 15 February 2017
I don't have any sources and this is strictly speculative, but I think support is being pulled because the service didn't catch on on these devices. PS4 probably makes up most of the usage of the service.
e=mc^2
Gaming on: PS4 Pro, Switch, SNES Mini, Wii U, PC (i5-7400, GTX 1060)