I think with a lot more people (including myself) going digital people will be more invested in one side or the other and will be less likely to change. I agree with you that this isn't marketed at most PS4 owners. I know a lot of my friends list that were staunch 360 gamers went PS4 due to MS messing up the XB1 launch message. A few of those may come back to XBox if they like any of the differentiators i.e. backwards compatibility, EA Access, XBox Live and option of an Elite Controller. I think Scorpio is mainly aimed at keeping the XBox players they've got and possibly getting those that haven't upgraded from 360 to upgrade.I think Phil pretty much nailed it here. I believe the notion that your average gamer will simply buy multiple machines which by and large play the exact same games is complete fiction. I used to have multiple systems as well, but back in the PS2 days, I had all the time in the world, not to metion each system sported vastly different libraries. Besides offering a big-ass visual boost, there were plenty of other reasons for a PS2 owner to buy an Xbox. There are very few reasons for a PS4 owner to buy an Xbox One now, and I believe the same will hold true for a PS4 Pro vs Scorpio scenario. The average Joe already cares very little about the PS4 Pro improvements. And unless he owns a big-ass 4K screen, why the hell should he? Seriously, what's a machine with 2 additional teraflops gonna do for him? Sorry, but anything that has to pretty much be pointed out in side-to-side comparison stills isn't gonna sway masses of people.
I would count myself as a definite XBox fan. Not a fanboy, but a fan. I bought the XB1 knowing that it was the weaker hardware, but I liked XBox Live more than PSN, I mainly play online shooters, not the single player story driven games PS are better at and I prefer the offset sticks on the controller. A lot of people like myself will order Scorpio Day 1. I've been wanting smaller hardware increments more often for ages. A 6 to 7 year lifespan is just too long. With PC hardware developing as fast as it is consoles get left in the dust and PC gamers start to complain that having to cater to consoles holds back PC games as well. I'm probably a perfect example of MS's target Scorpio audience. An XBox fan with a 4K HDR TV ready to go.