I'm gonna guess it's because your a jerky pants! lol No, I would guess they probably did some adjustments to factors relating to faction power/potential. They could have also played with predisposition factors. Like your size, potential threat and the likes.

These are the days that try men's souls.   The days of balancing.  

I can't believe some balancing caused 65 races to go DoW, however.

What I do know...well, that's a pretty strong word, I admit, maybe what I should say is what I do...is that at every update, I start clean.  New galciv3 directory, copy my factions and mod races only forward, delete the program data Stardock directory.    Just got in the habit.   With updates flying out pretty fast, that means big galaxies will just wait a bit. Maybe for 1.1 I will give it a shot.

I don't remember any huge adjustment that would cause that in the changelog, either, by the way.

There is an ideology trait which says "If you sack my home planet the entire universe declares war on you."