The more I think about it, the more I think the princess has shit reason to be who she is. She blames the goddess for "abandoning" the hyumans, but hey, the goddess love the hyumans and give them her blessing. And despite having been blessed, they still LOST. The hyuman probably looked down so much on demons they underestimated them and got owned. I say it's karma.
The goddess is already helping the hyuman with the blessing. If you lose despite the blessing, you shouldn't be looking at your benefactor, but at yourself and ask why you suck so much. The demons, though unfavored, were still able to overcome the odds, kudos to them.
Giving heroes to the hyuman is a second chance of sort to me. You're not supposed to go beg the gods for every trial that goes on your way, you go overcome them. You do not stay a baby with parents to baby you all your life, you grow to be able to take on the world. Lily is nothing more than a brat throwing a tantrum.