I think the PS4 is running at 60fps which was the whole point of running it at 900 vertical instead of 1080, at least for Battlefield 4. CoD Ghosts runs at 1080 vertical at 60fps. So comparing high/ultra at half the fps is a pretty pointless comparison. Plus it's not as though Battlefield 4 is playing on Medium settings on the PS4. I should probably just take the shrinkwrap off my copy and play it to see for myself.

And a lot of the technicals on PC building are nothing new to me since I started building overclocked gaming PCs in 2008 when it was brought to my attention that almost every game I bought for the XB360 was on PC. When it became clear that 720p at 30fps was the norm, I built PCs with a 1080p/60fps target for most games. I have a huge catalog of games on Steam and a bunch more on Origin so it's not like I'm some sort of console cheerleader/pundit. 

And a wii is two gamecubes ducktaped together. PS4 confirmed for nearly half as weak as the wii.

Still a massive framerate reduction when moving from high to ultra quality settings.
Battlefield 3 was the same though, things like HBAO can take a toll, some people can't really tell much difference on such subtle improvements anyhow.

Plus, who says you only had to have a single 5870? :P You can pick them up for the cost of a years worth of Xbox Live! Gold today.
The other benefit is, some people really don't care much for 60fps, so you can always drive up the image quality. - Personally I wan't both, rarely do I get either due to the resolution I run at.

That's always going to be one of the advantages of PC building; you can always pick up old parts whether used or excess inventory for the price of a song although I'm no longer turned on to the idea of picking up one video card today and then picking up another for a lot less two years later when I'd rather just buy a current card with more VRAM and additional features. The big problem with crossfire and SLI beyond increased power requirements, additional temp management, etc. is that you can't increase the amount of available VRAM by adding more cards. 

2GB cards are available in the mid-range today whereas high end cards from just a few years ago had half that.

All that aside, I still consider 60fps to be something of a personal standard. I've played games like Crysis years ago with the quality turned up at the cost of framerates, which may be fine for the wow/pretty effect, but not so much for smooth playability. If all one cares about is the appearance rather than how smooth a game plays, that's a big indicator that they're more benchmark players than gamers. 

Tagged. The more infos I get, the better, next year I'll build my next PC and I want it to be low cost and low power consumption, but powerful enough for every 8th gen game at 900p or 1080p (and so also many 9th gen ones at low settings).
Also for noise concerns, an APU with a downclocked mid-range GPU is a very good solution, to reduce the number of fans and to use a bigger and more silent one than the small, pesky ones normally used by discrete graphics cards.
During 7th gen my current low-power PC ended up not being enough powerful for the most power-hungry late gen games, but thanks to 8th gen consoles having favoured the birth of more powerful low-cost PC components, and also thanks to average screen resolution having grown slower than GPU power, this gen it will be easy, for those like me, happy with 900p and 1080p (and even 800p on notebooks), to build a longer lasting PC.