This has been answered in 4 or 5 threads very recently. EVGA is partnered with Intel and Nvidia. This answer is being answered constantly now.

 
Because EVGA does not want to tarnish their good reputation.
 

If I had a nickel every time someone asked this, I could retire early. Maybe pick up a small mansion, and a 1070 from a scalper.
 
I think the biggest reason EVGA doesn't do AMD is the deals they've had with Nvidia and Intel for years; it might be more profitable for them overall to continue on as they are.
 
It might also be the part of the market they target. Not trying to bag on AMD, but if you've noticed EVGA is a little pricier and is shooting for quality and performance. AMD is overall more budget and value oriented. That's the impression I get, anyway.

Depending on how big of a competitor AMD will become, these things might change - or so I hope :p


Also, I can definitely see what @gipothegip is saying

Because EVGA doesn't make heaters.

Hoggle
I think the simple answer seen if you go to Futuremark and filter by graphics card popularity. The 1080 Ti, 1080, 1070 and the 1060 make up 44.08% of the benchmarks for July so far. The top 8 AMD cards only totaled 10.01% of the tests.  Customers just seem to like NVIDIA more https://www.futuremark.com/hardware/gpu 

Some nice info from the above link for CPU use https://www.futuremark.com/hardware/cpu/

AMD would sully the EVGA brand.
 
EVGA is master class not space heater class.

 
Moved to General Hardware.

quadlatte
every year around this time the same questions get asked by the new people that sign up for the giveaways, like clock work. short answer is evga is a intel and nivida partners, no other reason and i dont see that changing anytime soon.

+1. That is the reason.
 
However, I'm sure like any other company EVGA will keep an eye on the market to see if any changes are warranted. 

candle_86
Because EVGA doesn't want to appear to be a cheap hooker like ASUS, taking it from just any hardware manufacturer 

Most manufacturers do.. XFX and EVGA are exceptions

Partnerships

EdhuCesar
Because EVGA doesn't make heaters.

 
They tried making a heater, but it didn't sell great.
Thy sent this thing to me in place of a dead GTX295, I couldn't sell it fast enough.
Shoot, my GTX 295 (two of them) Dual PCB ran hot with the stock coolers, would hit 85*C.

miscbyproduct

Scarlet-Tech
This has been answered in 4 or 5 threads very recently. EVGA is partnered with Intel and Nvidia. This answer is being answered constantly now.

doesn't mean much, as they can also "partner" with amd, if they choose too.
 
 

I'm sure that if EVGA wanted to they could make one of the best AMD graphics cards available but EVGA is an NVIDIA partner at this time. I don't see that changing unless there is a drastic market change.

miscbyproduct
other's manage to license both nvidia and amd.
and staying in business doing it.
 
i suspect there is more reason for a co choosing to ignore such a large "otherside".

The "otherside" hasn't been a competitor in many years, until very recently.

Why doesn't XFX make nvidia gpu's?

Wiki says:
"Originally, XFX only produced Nvidia graphics cards; however, during the beginning of 2009, XFX decided to begin manufacturing ATI (now AMD) graphics cards as well. Nvidia disapproved of this decision and removed XFX as an official partner. As a consequence, XFX was unable to produce any of the new ("Fermi") generation of Nvidia GPUs.[2]"

Why doesn't sapphire make nvidia cards?

Probably the same reason as XFX. Probably something to do with why EVGA is nvidia/Intel exclusive. We could probably sit here and speculate forever. EVGA is the only ones that could answer for sure.

Scarlet-Tech

miscbyproduct
other's manage to license both nvidia and amd.
and staying in business doing it.
 
i suspect there is more reason for a co choosing to ignore such a large "otherside".

The "otherside" hasn't been a competitor in many years, until very recently.

Why doesn't XFX make nvidia gpu's?

Wiki says:
"Originally, XFX only produced Nvidia graphics cards; however, during the beginning of 2009, XFX decided to begin manufacturing ATI (now AMD) graphics cards as well. Nvidia disapproved of this decision and removed XFX as an official partner. As a consequence, XFX was unable to produce any of the new ("Fermi") generation of Nvidia GPUs.[2]"

Why doesn't sapphire make nvidia cards?

Probably the same reason as XFX. Probably something to do with why EVGA is nvidia/Intel exclusive. We could probably sit here and speculate forever. EVGA is the only ones that could answer for sure.

I think someone put its own conclusion on wikipedia, the cited source doesn't corroborate what stated in that paragraph. We actually know almost nothing except that they didn't agree on something, they may have loosed the status of "special partner" and entirely dropped the production of NVIDIA graphics cards