Quite often the 30 year olds droning on about it have their youtube channel/businesses geared to benefit from the predictable crowds of kids. There's a lot of traffic, and a lot of channel growth in it. To capture the most traffic, you show your purity in your tribal group - you bash the other platform harder than your competitors. Repeat to the extent that platform choice becomes a character defect of anyone who chooses differently.
I remember 'my' console war of PS3 vs 360 at school in like 2007, the motivation at least made sense. I was trying to convince my friends to pick my platform so we could play together. This just seems bizarre.
If anyone has read Jonathan Haidt's "The Righteous Mind" the psychology of tribalism will be familiar. But fundamentally the human mind doesn't have "politics" and "not politics" as fundamental categories of thought. We're chimpanzees with big ideas, and once we get the sense that we belong to a tribe, we're geared to treat insiders and outsiders differently, as in politics as in console wars, our minds make no distinction. This article I read a few weeks ago was quite fun https://www.tandfonline.com/doi/full/10.1080/1047840X.2020.1721233