>>58947601Because change bad. Must always conform to the same formula, otherwise that would be different, and different is bad.
Must always have 8 gyms, must always have victory road, must always have elite 4, must always have type-themed gyms and elite 4. Must always have three designated starter pokemon given to you by the professor, which must always be grass, fire and water. Must always have a rival that ends up with the starter with a type advantage over yours. Must always release at least two games every cycle with minor differences.
Any deviation from this formula will be met with hostility from the fan(atic)s. They want the same thing every single time. It's the same for people who eat McDonalds every day; if the taste was even slightly different they would get mad.