They were actually planning to implement something like this, before settling on a cut down version for 0.13.

The big issue is basically... that it's not a tree, it's more like a web, and it becomes very hard to read if you try to display it in such a fashion.

Yes, the screenshot from Civ is ...

Userstory would be as follow:
"As a player, I want to have a clearer display of the technologies' dependencies so that I can see in a second what technologies I need to research to unlock what I want" (I'm not great at writing user stories, sorry if it's not clear enough)

To better illustrate what ...