[quote=@Legend]
<Snipped quote by GalaxyRaider>

I thought that smaller and weaker groups weren't normally targeted. I don't know for sure, but if I were a bad guy, I don't know why I would go after some random planet that can't do anything about it, or even how I would know they exist.
[/quote]

When civilizations die, it's not usually due to some form of targetting. It happens by chance, or by simply winning some jerk's mental lottery. When a bunch of insignificant species band together to protect themselves and one another, the random elements are taken away. And, not only are you out on the map for bad guys, but you're also now on the map for good guys as well.