PvP in PP V2- rewards for both attack and avoiding attack

[Rubbernuke]

But with a big enough galaxy why would I do that instead of getting more territory for my own power unopposed?

Because not all systems are equal. From the stream it was stated systems have a score based on population and other metrics- so that tin shack outpost is worth less than a core world. And that striking these high value systems really messes up powers.