Sony themselves said that they bleed users to the PC platform as their tech gets old. PS4 Pro is a mid-gen. Four years for another console seems decidedly risky for what Sony want to prevent. When rumours of Pro was originally circulating, many didn't think it'd be launched in 2016 yet that's right where they launched it. Sony's reasons for Pro are likely to Microsoft's reasons for XBOX.
I wish I could see their data, ok there is a loss toward PC gamers but at the same time I don't think PC gamers that are into high-end give up on their hobby because they own a console. I'm not sure technical prowess is what drives gamers that are willing to shift back and forth from PC to consoles.
As a generation advance (and drive development) competitive PC parts are getting cheaper for people on a budget it is a good time to upgrade and access a lot of games sold significantly cheaper on the PC /if not play some older games. It could be that update cycle for lots of PC gamers (with reasonable gaming budget) is shifted from the console pace of release, that does not means that higer performances is the driver for them to move back to PC and let their console collect dust:
PC can be a cheaper alternative.
In the console realm neither the hardware cost nor the software follow the aggresive reduction found on PC.
I might be off but manufacturers are more and more about high-end and they are aligning their expectations and line of product on the request of a limited but wealthy group of gamers (wealthy or with a significant budget inested in gaming). I don't know if it a good or a bad strategy BUT clearly I think a lot of people that are more price sensitive are attracted to PC, the price to get in is a little higher but it has its benefits in the long run (on top of providing the functionality a PC provides outside of gaming).
Now consoles manufacturers are moving toward foward/backward compatible products, they have the higer end cover but if they want to avoid the leak toward PC they might think about covering the lower end better along with more aggressive price reduction for the software.
Yesterday I've only bought middle-earth:LOTR BUT for 10€ I could also have bought brutal Legend, a good sonic racing game , new games no online fee (ultimately I hesitated too long and the callig of the bed got the best out of me). On steam I received for free updated edition for darksiders games and titan quest, such thing may happen with other releases. I'm an extreme case and not that profitable as a costmer, I'm litterarily one generation behind but thare are many shades of grey between "software early adopters" and "last gen enthusiasts".