For me, I started off the seventh gen owning an Xbox 360, and being young and essentially broke, I had no reason to try owning both consoles; at the time, it was a no brainer for me, as the 360 had games like Bioshock (before it went multiplat,) Mass Effect, Crackdown, etc, as well as having better multiplat quality and being cheaper. Owned it for a few years, and when it eventually broke, (post-warranty,) I decided that rather than buy a new one, I would instead buy a PS3, which in the ensuing years had seen a solid price drop, and of course had all kinds of exclusives I'd never gotten to try before, as I'd pretty much played everything that interested me on the 360 up to that point. Of course, there were still a few years to go, and I figured that I would eventually buy a 360 as well, probably two or three years down the road, and then get to play all of the exclusives that had released on THAT system during my absence. Genius! ...except it's been five years since my 360 broke, and I've seen zero reason to buy another one, even used. Because it just so happens that,
There was always that whole 'Lawl PS3 has no games' thing in its early lifespan, but when I actually did a comparative look between the libraries of the PS3 and Xbox 360 from the launch of the original Kinect onwards to the pre-8th gen period (because that's roughly when I 'switched' from one to the other,) it was actually the polar opposite. o.o PS3 has a solid lineup of varied titles, both Western and Japanese, whereas if you didn't own a Kinect, the only break you'd get from Halo, Gears and Forza would be a few PC-ported titles like the Witcher 2, Minecraft, and I believe a Toy Soldiers game.

And as someone who never was that big a fan of Halo, (which I enjoyed, but wasn't a 'console seller' for me,) Gears (which I rapidly lost interest in after chainsaw-ing the fifth enemy,) or Forza (to be fair, not a fan of most racing games,) I had pretty much zilch in terms of incentive to return.
As the reveal of the 8th gen consoles approached, however, I saw it as an opportunity to take a look at both sides of the fence; not tied down to either side, I would choose the console whose announced lineup and features were best for me, personally! Huzzah! So in order to make the best judgement, I waited til E3 to watch the now-months-old reveals for both consoles, then watched the E3 show for both sides. Wasn't even close, in my mind, PS4 it was.
The thing is, I wasn't planning to be a Day One adopter, in fact it was nearly a year before I hopped on at all, so I kept an open mind, watching both consoles closely to see how they developed. For me, the Kinect was a BIG sticking point; I had no interest in it, largely skipped the Wii because my mancave just does not care for that stuff, and spending an extra hundred bucks for something I neither needed, nor wanted, was a big 'Heck No!' And, of course, it eventually was dropped, and I decided 'Okay! This might be a tough choice after all!' Up until news got out that one prior exclusive after another was moving to PC, meaning I could just hop on my roommate's rig to play it all I pleased... it definitely let the air out of the Xbox One's tires for me. Not just because of what titles HAD gone to PC, but because it led to the niggling question in the back of my mind 'What OTHER games, among those they've announced, will end up on PC?' Spending money on a console to play some awesome games, I don't mind- I'm going to need to spend a good chunk of change to upgrade my own PC enough whenever Star Citizen graces us with its presence =P - but spending money on a console, only to realize I could have just waited six months and spared myself the expense, is less appealing a prospect.
So, yeah, I don't dislike the Xbox One, it's just that right now I don't feel like it's a terribly reliable option for me. o.o The only titles that are all but guaranteed never to end up on PC don't really interest me anyway. Having played the crap out of Infamous: SS and Bloodborne, among others, I'm quite pleased with my choice of console, and have no regrets, really.