My point is that these characters have certain traits that have been preesented as a part of who they are for a while. Both discord and twilight want the same thing, the difference is that twilight's side isn't completely explained yet but Discord's reasoning was fully more or less so there is a disconnect for some at the moment. From what we about twilight when trying to fix a big problem can often freak out known as twilighting or jump to conclusions. That's just a part of her character. The **better and/or bigger question** that should be asked, is why would the rest of the friendship council consisting of the mane six and spike, why not even starlight, trying to help her come up with a different plan? or have a different mindset? Rather than why twilight as a character decided to go this route. Knowing the characters they all would have differing ideas on what to do, but then again the backstory isn't fully explained yet. Because right now they all look like a hive mind of
If I were to get political and akin it to the real world twilight set up gun control because everyone was using guns against each other basically. There is ofc issues with it like if no one has ~~guns~~ magic, how can they protect themselves or what's stopping them from fighting without ~~guns~~ magic. But quite literally no such thing as perfect plan, every decision has it flaws, to me twilight went with the best route that was presented to her.