@DragonBoi471
Based on what we got in the G5 film (which is very little), I can easily imagine a pony dividing the 3 magical stones just because he had a bad and horrible experience when it comes to friendship with one or more unicorns or even a group of conflicting unicorns who wanted to mess with him or her. And remember: One of the devices made by Canterlogic is a helmet that protects earth ponies from mind control magic. I’m assuming the pony who divided the pony society
had experienced something like that, and because of that, he splitted the magical stones out of spite.
I think most of us have experienced something like that, a person who manipulated us out of spite, and, as a result, we ended up hating everyone and everything. Some people can get over it after 15 minutes and other less patient people wanted to take actions on their twisted way.
I don’t think this has to be true, but I can see that logic: Someone who wanted to divide a society because of a bad experience he or she had.