Care to actually back up that statement with any sort of citation or fact? According to the leaked 3dmark benchmarks, the top 3 Ryzens are on par with some of the top i7 quads... so honestly I'm not sure where you are getting this idea from. It also completely ignores the price disparity which makes the AMD slightly slower but much cheaper CPU's a doable upgrade for many. (And VR capable)
Here's results from actual games:
http://www.gamersnexus.net/hwreviews/2822-amd-ryzen-r7-1800x...
Even the older 4790K is sometimes faster. And the i7 quads are cheaper. So games prefer higher clocks to more cores, that's still true.