Unity’s hardware stats don’t disagree - you can see it easily from the GPU statistics:
http://hwstats.unity3d.com/editor/gpu-win.html
Nearly half of Unity developers are apparently using Intel onboard graphics, and amongst the most popular non-Intel cards are Nvidia onboard graphics.
If you look at the mainstream ‘serious’ development cards, most have no significant user share at all (GTX970 1.7%, GTX1060 1.2%, GTX980 1%, R9200 0.8%).