[PinkMilkshake]

What do you mean by 'worthwhile'? And what would worthwhile be to an alien?

For all we know, the universe is jam packed full of Predator-like aliens who are the dominant species on their planet specifically because their society is built around dominating everything they can.

[AnIdiotOnTheNet]

Well that is a fair point, we only have one example of a species capable of building civilizations to work from. It seems unlikely, however, that we are going to end up being particularly unique in that class.