Neither AMD nor Nvidia have anything to gain from GeForce cards performing poorly with Ryzen. There's no foul play here.
-AMD still prefer if you pair your GeForce with a Ryzen rather than an Intel CPU.
-Nvidia will gladly sell you a GTX 10x0 for your new Ryzen build, they're not going to deliberately sabotage performance and steer you away from GeForce just because AMD also happen to make GPUs.
As usual with Ryzen, things tend to get very emotional and overblown. A few games, mostly DX9, seem to not perform optimally with Nvidia cards at the moment. Doesn't mean there's a big controversy or something is "broken" and needs "fixing". It just means Nvidia, like everyone else, will have to profile and optimize for this brand new architecture. I'd expect these few performance anomalies to get fixed and general performance to improve in the next few driver updates.