Yes, games and nearly every other application have been developed day-to-day on Intel/Nvidia hardware. So, problems with those two are "immediately" noted and fixed. Moreover, for bigger titles, Nvidia almost always helped with the graphics programming. Even an Nvidia Engineer once said (paraphrased) "they put their thumb on the scale" to make sure Nvidia scored best. Even now many use Intel optimized compilers that default to less optimum code for AMD products.Moreover, developers look to "save development cash" (as an ex-Project Manager, I know how costs spiral up out of control on many projects -- not mine, of course ). One way to save money is to develop on the dominant hardware and virtually ignore the competition (AMD) -- which saves person-years of effort.

The deck has really been stacked. AMD hardware is not as bad as it seems. Often AMD was a couple years ahead in actual features -- but few or no-one used them because Intel/Nvidia could not support them (tessellation comes to mind). AMD is/was ahead of Nvidia in DX12 and Vulcan graphics language support. Meantime, new Intel/Nvidia features are supported within months. Its always been "uphill" for AMD.

Up to now, if one was totally objective and price conscious, one could get a competitive gaming machine buying AMD products and save cash. I did -- of course I built so many machines just for fun that I spent more in-total than a price conscious Intel/Nvidia fan. If one wanted the highest performance regardless of cost, then Intel/Nvidia was the way to go and still is in April 2017 -- while most games and benchmarks are still Intel 4core optimized and Vega is not "on the street" (expected in 6 weeks).

However, that is changing. Ryzen works as well as the Intel products now -- maybe a little better or a little worse depending on the tests. But, this is Ryzen's first product on the street for less than two months. It will get better during its first year. I expect Intel/Nvidia to be competitive hardware-wise but not overwhelmingly so -- just competitive.

In 6 weeks, we'll begin to see Vega growing pains. But, Vega is not a brand new path for AMD. Its the old-path perfected. AMD Navi GPU due in 2019 will be the "new approach" that Ryzen was for CPUs. Nvidia needs to have an answer just to stay competitive.

Regarding software. Some game companies are starting to work with AMD -- the major consoles are AMD 8 core CPU units with AMD GPUs -- these days most games are Console-First, PC-ported. With a popular high core count Ryzen on the streets (and Intel caving in to provide high core count gaming CPUs) high core count is where it is headed for gaming. Those Intel 4 core units will no longer be the best -- and Intel knows that. AMD actually leads that race. Intel will be competitive -- they won't lose -- but, they will no longer "stand alone" at the head of the pack. If no big problems arise, they and Nvidia will have strong AMD competition across the board by the end of this year.

AMD has a plan in place that, if successful, will jump them just slightly past Intel/Nvidia in two or three years (e.g. Navi and very high core count 7nm CPUs) -- across the board in all product lines gamers care about. Not enough to turn off Intel/Nvidia fans, but enough to be a solid part of the conversation and have their products equally well supported. Then, it will come down to merchandising and price. AMD will probably hold prices down to catch the eye of the Intel/Nvida fans. Of course, Intel/Nvidia could drop their prices too and will at some point.

So, we are at the edge of the "new era" where Intel/Nvidia has serious competition and will have to "step up". Who will win? I don't predict which company (though I see some near term technical pluses for AMD -- offset by Intel/Nvida cash and brand awareness). I predict the winners will be the customers, the gamers. They will get more for less than they would have if Intel/Nvidia had been unchallenged.

All the above is my non-expert opinion, of course

Competition is good