Hannibal nailed it perfectly. We can't just base ourselves on activity, it's very unrealistic and prone to all kind of exploits. We could have something like Bowex vessels idling in space with 5 ships for two days straight to collect something like a 300% bonus and then just fly for an hour and collect an insane amount of money.
I'd be more in favor of a system actively rewarding players for their participation (ie: Skyforge invasions), and that's what the event system is intended to provide. I have many ideas for all kind of stuff to reward players and especially cooperation, but I have little free time right now. To be entirely honest there's also a serious lack of motivation on my end these days as most of my time spent on disco is lost to trolls disrupting the game in one way or another.