I can't remember them to well, but gorilla general and mob face minister aren't portrayed with your typical run of the mill villain faces. Are they really evil or just a bit selfish?
So the princess's reason is instead of helping him the best way she could, by opposing the other faction in the castle, she decided to be a weight at MC's ankle and give the enemy all the reason it needs to persecute MC. All because she wanted to warn him. Not because of being delusional in love. Sure. Why should she send a trustworthy messenger like her maid, if she can creating a ton of other misunderstandings, for the enemy to cherry pick its favorites from. I understand, that they would have found another reason, but now they have a pretty good one. (Or maybe this is a blessing in disguise, as the princess can vouch for MC. But let's face it. They'll call it stockholm syndrome and its usefulness is waved away like this.)
I can't believe I'm writing this, but I'm with MC on getting that other annoying princess about. This way she does less damage and she'll see herself, that the others are lying.