It's easy to do when the first party software is so consistently solid :P (for the most part - you've got occasional stinkers like Mario Tennis Ultra, Star Fox Zero, and Wii Music). Plus there's tons of them. There's also some great 2nd party stuff like Xenoblade, and I still buy the occasional third party game for Switch (more on the indie side but still), namely for the portability.

Anyway it's not the brand I'm loyal too, it's the quality games. And at least for my money, the games that appeal most to me just happen to come from Nintendo more often than not, with some stuff on the Xbox front too.

Sony tends to lean on the style of gaming that just doesn't appeal to me as much, which is more linear, cinematic games with an abundance of fluff like dialogue and cut scenes. I prefer to get into the action as quickly and as much as possible in addition to maximum freedom.

Home console, sure. Portable, not sure 

No, the context is still important.

If they ask 1000 people about home console loyality and only 50% of them are home console gamers, they only have 500 valid answers.

If they ask 1000 people about handheld console loyality and only 25% of them are handheld console gamers, they only have 250 valid answers.

If they ask 1000 people about VR headset loyality and only 10% of them have a VR headset, they only have 100 valid answers.

If two third of the surveyed people live in the US and only one third lives in the rest of the world, there will be a strong local bias in the answers.

If two third of the surveyed people live in Europe and only one third lives in the rest of the world, there will also be a strong local bias in the answers.

...

My first PS1 developed a problem with the laser, so I had to buy another one. After that, no problems with the next iterations. I don't remember any widespread issues being reported here in Europe at the time of those consoles. Maybe we got a different batch over here or something?