I see a lot of hype about being able to pet dogs in video games. Why?
Because people like dogs. And like to pet them, even virtually.
It’s because it’s a feature 0 people will complain about adding if it all works well. It’s a small, minor, completely unnecessary detail.
If it’s there, then someone had the time, the energy, and the freedom to add it, just because they wanted to. It’s not an item that will make it on the checklist of a minimum viable game.
If it’s there, it’s a very good sign.
I’m thinking because it’s as nice as it’s pointless, thereby showing that the devs were detail-oriented in how to delight players.
When you see a dog you want to pet it. It’s nice when they place that little extra detail.
Because people are wowed by the simplest of things.
To add to the other responses, I think there’s maybe a sense of relief or novelty in it, as the rest of many of these games are intense and/or violent. Having a little wholesome moment in the midst of all that really stands out.