Xbox has been sucking hard for decades with that shootbang boring racing shit. Second, Nintendo is seen as a homogeneous entity that can only the same output kiddie/ family friendly content in an effort to be the Disney of videogames. A lot of people don't even realise Nintendo has several devs under their house. Sony has a long history of much more variety for their best selling genre games. They went from platformers to racing games to 3rd person adventure, and while their diversity has narrowed since the PS2, it's still seen as the most to offer. You can have siblings each with popular titles that are completely different, while Xbox is the Gears/ Halo/ Forza machine and Nintendo seen as the Mario/ Zelda Smash box. If a casual doesn't like those titles on Xbox and Nintendo, they don't dig much deeper for options, while with Playstation a casual who doesn't FPS racing games or platformers can still find well made, well reviewed games easily.