Again, source please. The only thing I'm finding is this clip of him walking into a bathroom. There's also no mentions of Alinity cheating with anyone and only rumors of her doing sexual favors with Twitch staff. Nothing solid.
The backstory for these particular comments are that she made joke after Ninja's wife was having a fight with another streamer, xqc. The fight is above alinity and Ninja's comments. Ninja and his wife just took her joke wrong.
It's because it's an entirely one sided selfish love. They don't consider the other person's feelings and either don't care or can't understand how that makes that person feel. It's in part due to how they idolize them. They pretty much dehumanize them whether they realize it or not and see them as the object of their love rather than a person they love.
I know that some do have real pockets, jus that they're sown shut. I think to make it look better on the shelf, not too sure on that. Other than those exceptions, I'm not sure myself why they are.