I have no loyalty to any of these companies anymore. That said, I definitely had some fanboyism growing up. We only had NES, Gameboy and SNES growing up and there was a lot of arguing on the playground, cafeteria etc. between the Nintendo kids and Sega kids. Then my first online forum was an N64 site (N64HQ or something like that) that I was on a lot in the lead up to launch and first few years of that generation. That was of course a fanboy haven and further continued my fanboyism.
I eventually played some games like RE1, FF7 etc. at a friends place and loved those and got a PS1 and have had multiple consoles since. My Nintendo fanboyism still lingered, just less intense. I got a GC first next gen, and then a PS2. I was pretty anti-Xbox early on and argued a lot with their fanboys online. I was all about Japanese games and didn't care at all about FPS, WRPGs etc. back then. Eventually got one an Xbox for KOTOR and loved that, really liked Halo 1 and 2 etc. That finally killed my fanboyism in my early 20s. I did get a Wii first the next gen, but I was pretty ho hum on it and just got it first as I was a poor grad student and had to wait a bit for price drops/sales to afford the 360 and PS3.
Now I don't give a toss about any of this companies in terms of having any loyalty to them or feeling any need to defend them or attack them beyond calling out practices I think are shitty by any of them. Nintendo hasn't been my most played console since the N64 generation, PS2 was most played, then 360 and then PS4. Like many, I do have preferences given the genre and style I like. Since late last gen when I got a PS3 I've been mostly Sony--but only because my currently favorite games are cinematic, third person, narrative driven, action adventure games and that's the bread and butter of their exclusives. My Switch (and Wii U and 3DS before it) have also gotten a ton of play, as does my PC where I also play Xbox exclusives (had an Xbox One for a year or so before Play Anywhere).
As for why there's still so many fanboys on a site like this were most people seem to be 30-40 somethings who should have grown out of it, I think it's a few reasons.
-For some the reason never changes. They can only afford (be it lack of money or lack of gaming time) one platform. Their fear of missing out makes them need to feel like they made the best choice with their limited time and/or money and don't want to feel like they're having a lesser gaming experience than people who own the other platform or can afford/justify multiple.
-Lot's of social rejects who just need to fit and and belong somewhere. They end up banding together with other fanboys and end up stating hyperbolic opinions, getting in heated arguments with the "other side" as it earns them internet points from their "friends". Same idea behind SJWs and whatever their otherside equivalent is. People have become more and more tribal and wanting to find some niche to "belong" to, and this seems far worse online than in the real world. It's especially bad on things like Reddit where there are console specific subReddits that are fanboy echochambers.
-Lot's of losers whose identities are just way to tied up in their hobby and the intellectual properties they enjoy the most. So if they're tied up in exclusive IP they're going to be a fanboy as it feels like a personal attack on them that the thing they care so much about/have as part of their self image and self worth isn't viewed as the best (or at least good) by others. Even for folks who aren't that extreme, having a lot of time and nostalgia invested in IP can lead to feeling a need to defend it.
And I'm sure we could come up with a host of reasons, and none of them justify adults being so invested in a damn media consumption hobby, nor feeling the need to do free marketing for huge multi-billion dollar corporations who don't give a shit about anything but getting as much of our hard earned money. I wish mods/site owners would do more to put the kibosh on fanboy bickering--but I get it leads to high traffic threads from people arguing and hitting F5 to see replies and keep posting again and again to try and get the last word and that means a lot of ad views.
