It's actually very simple; it's https://en.wikipedia.org/wiki/Conway%27s_law in practice. There is no "Linux" operating system, only an endless assortment of independent people and sometimes companies, each of which builds whatever they want, and sometimes they assemble some of those pieces into a working operating system. Every time someone makes a distro, they have their own vision and they run with it. Every time someone doesn't like a component, they fork it or make their own thing. There is nobody who can impose a single order, because it's just a loose collection of separate groups, several of which are actively feuding at any given moment.