My most recent GPU purchase was a 980Ti, upgraded (IMHO) from 290X Xfire, certainly no corporate fangirl.
It sucks that the gaming industry in large focused on consoles and PC's became an afterthought for the most part. Couple this with the fact that both of todays and the next consoles sport GCN, we are bound to see more and more GCN optimised titles.
I created a whole thread to debunk this myth.
It was quickly shot down by tons of people who had no idea what they were talking about or went off on some unrelated tangent.
But anyways, PC versions of multiplatform games are more prioritized than they have EVER been in the history of multiplatform games. So this is patently untrue, already. And in fact, there's quite a lot of games that are built for PC first, console as a later priority.
As for there being more GCN-optimized titles, this is possible, but not necessarily a given. For one, PC development has a lot more than just different GPU architectures to worry about, and in general, they dont optimize towards one specific spec because it's not good business to only run well with one brand. In fact, any brand that considers PC as a serious platform would probably not prioritize one brand over another, especially not a brand that makes up a minority percentage of potential market. In the end, DX11 makes this abstraction quite easy to deal with.
The fact that AMD GPU (PC) owners are getting free performance under DX12, as they are no longer at the mercy of the frankly "old dog" like DX11 drivers; is great for them. Nvidia will not see such benefit as their DX11 drivers were simply "that good" to begin with that the hardware is nearly always able to hit it's full potential.
They aren't getting 'free performance' at all, though.
Once again, I think people completely misunderstand what DX12 is. Or even what DX11 and API's are at all. Most of DX12's feature-level capabilities have actually been recently been enabled in DX11.3.
You are correct that Nvidia will benefit less with current architectures because their drivers were always way ahead, but as I mentioned elsewhere, this may not negatively affect them unless they commit the same strategy when these API's are more commonplace. They're probably well aware of all this, though. Nvidia are a very 'here and now' company. For better or worse.