Yeah, in the end, they're both just afraid of losing each other and are trying to protect one another in their own way.
Maxi can't accept Riftan's decision because she's terrified of putting Riftan and Anatol in danger. And so is Riftan. He's just as afraid of losing his precious wife—to the point that he couldn't care less about anything else, even if it meant going to war against the nobility or even the Crown.
And unfortunately, neither of them are capable of, well, any communication at all, never the less honest communication. And their stubbornness regarding the other, the desire to protect and not lose regardless of the others wishes, means that even if they started to learn how to communicate, the other party wouldn't listen.
The main reason I keep following this story is because of how funny it is that Riften and Maxi are extremely similar

Both Riftan's reaction and Maxi's decision are completely understandable. I can't blame either of them.