I was hoping for something along the lines such as what I've seen in some video games and animes. Effectively I was hoping that the Reapers would monitor organics and when the rate at which they consumed resources hit a certain point they'd reduce their numbers. It's been done a few times where the human population was controlled to prevent the destruction of earth or in some settings with several species to keep one species from dominating the others.
I forget the name but there was one game in which every species had a dragon to represent them. When one species grew too powerful though the gold dragon would show up to knock them down a few levels. Humans had been knocked down around three times I believe and the silver dragon, humanities representative, was sick of it. So it guided humanity into a war to exterminate the dwarfs, elfs, their dragons and especially the gold dragon. I empathized a bit when I looked at it from his point of view. You've nurtured three great civilizations that stood above all others and then this ****** comes and destroys your hard work. Wouldn't you be upset?
That's off topic though. Anyway, keeping the organics from using up all the universes resources before a way can be found to reach other galaxies seems like it'd be a good cause to me. Though if that was the case I would advocate birth control.