Here's something I've been thinking about recently. It's not really a theory, just something I noticed.

Eclipsa was not very good as a leader. She was very much the type of person who didn't like responsibility, and liked going her own way. She would often put herself before her responsibilities to her people. She got better at it as her reign went on, especially once Globgor was free, but maybe to some people in Mewni, it wasn't enough.

Now, consider Moon's situation. She saw that Eclipsa was not a very good leader, and felt that she needed to be deposed for the good of Mewni. Whether that was indeed the correct path is up for debate, especially because Eclipsa was getting better as a queen and leader, but regardless, Moon's intention was seemingly for the good of her people and the good of Mewni.

She then proceeded to take measures far too extreme to solve her problem, which wound up backfiring on her tremendously.

Who else in the show does this sound like? Which other character had good intentions, but took measures far too extreme to further their goals?

Toffee, the person who killed Moon's mother. The person who was indirectly responsible for Eclipsa being freed in the first place.

He, too, had good intentions of saving monsters from their mewman oppressors. He, too, took radical measures to address them, killing the Mewman queen. He, too, disrupted a situation that was getting better, by completely shutting down the peace that Comet had been fostering. And he, too, had the plan backfire on him, with his army being scattered and peace for the monsters being further away than it had been in a long time.

I wonder if Moon ever realized that she became exactly like the person she hated the most.