What keeps NVIDIA on top are fanboys. Fanboys everywhere. Fanboys for as far as eyesight goes...
You're absolutely delusional if you truly think that.
Fanboys simply rant and moan and bitch.
Consumers purchase the solutions that fit them the best and it's up to the companies to sell that product. Fanboys also rarely buy the stuff they bitch about.
As far as the GTX 1060 is concerned, I'll be surprised if it it's more appealing than the RX480 once the AMD AIB cards are released (and reviewed). If it were my market slot I'd be awaiting on reviews of AIB's from both camps. Nvidia have priced way too high for my ethics bar this time on the 1080 front and if they do the same on the 1060 I think it'll backfire, as long as it's the same ball park as the RX 480. What will truly hamper the 1060 will be DX12 performance as you can see the 1070 suffer a bit on that front compared to the 1080.
But no man, get a grip of yourself, fanboys don't make Nvidia the top dog. Ruthless business skills and delivering products that achieve their stated PR is.