The Amazon thing can be turned off. Unity2D is acceptable on slower machines. My experience, of course. You have valid points, nonetheless.
but it was removed after 12.04 if I'm not mistaken. That is why I still use 12.04 on a couple laptops. I think the time is running out for 12.04 updates, so I will need to change to something else. There is always gnome-session-flashback, I guess. Not sure if the kids will like it/want it, as they're used to Unity and it's their laptops...