You don't want your money to change all the time. In fact, the simpler the base layer, the better. Simple means that it is not easy to make mistakes. The expansion layer maintains freedom, and anyone can display their creativity on the expansion layer. In fact, the basic layer is not always unchanged, after enough discussion and testing, it will be changed gradually. As for speculators wanting to experiment directly with everyone's bitcoins, I think it's irresponsible.