I'm with you there. How the frak were they safer with her? If you were an officer or soldier, she was likely to shoot you in the head on the spot if you questioned any of her orders, like she did to her XO/best friend (in her first sociopathic act, which incidentally happened before she learned about Gina). If you were a civilian... she would just leave you to die or shoot you to begin with, because you're just a useless puny civilian who can't fight the Cylons and the military is all that matters. If Cain had stayed alive, a civil war would've erupted in the fleet. And that's actually the better alternative compared to the other one - Cain gaining full control of the fleet, which would've likely meant bye bye to the 30,000+ civilians and the end to any hope of rebuilding the human race and the civilization. (That's why Roslin decided to have her assassinated when she learned what she had done with the civilian fleet.) Cain didn't care about that - she just wanted to hurt the Cylons. Her war was ultimately destructive and pointless. She had no goal except revenge.
It also pissed me off big time when Adama said at the end of Razor that she was a tactically perfect commander - when what we saw of her tactics on screen is that she walked right into a Cylon trap (which her XO warned her about and got a bullet in the head for it) and got half of her crew killed, because she was so eager to destroy the Cylons.