In this particular case I meant that linux is the same in all regards: open source. You can look everything up if you have the time. This makes it possible to change everything and anything you need. Even through different DEs you still have the same structure.

Now if you go try that with windows, you‘re properly hosed. Different package manager? No! Different desktop environment? No!

Simple might not have been the best choice of words though. Modularity might be better.