Because the post is not about aliens. It’s about people. Aliens serve here to help you see the problem from the outside, to not use what you know about the animal. It’s supposed to show you the reflection of our way of thinking about fossils.
It’s not just about systems, It’s about conditions. Certain conditions make certain strategies more profitable - see game theory. I think low population density and hard life conditions cam lead to kindness being among the winning strategies.
The primary difference is what it’s all about. You can ignore similarities with other restaurants like there’s food involved and such. The fact they are sitting in their cars is the point.
I like the way you explained not all the people on the phone are shitty parents! I think it’s a very nice and positive way of thinking about people. Just for the sake of balance I would like to add that shitty parents do exist, unfortunately. But I agree not all people that seem shitty at first glance are!
Possible answers include: Because this concept is not suitable for every city. Because there are other ways to introduce greenery into the city center, like many bigger or smaller parks.