And even then it was old!
Kind of! But that's why they combined it with the innocence of a young ballerina. Helps to subvert expectations through subversion.
This thing is more like a blobby tadpole.
Why would they shoot down their own ship?
Iron Dome isn't primarily designed to shoot down aircraft. It's there to target and destroy individual missiles and even mortar shells which are headed towards civilian areas. The urns would be easy for even a system like that, much less something millions of years in advance.
Who's to say they're are as violent to there own kind as humans are?
That's why I gave the example of asteroid strikes.
Stuff like that can come out of nowhere and you'd either want some kind of energy shield (which clearly isn't present here) or a way of destroying them before they hit populated areas.