Are smart phones the end of "never change a running system"?

Some smart phone software is like bananas - ripening in the phone of the end user. Why is that so? I really appreciate that my Android phone has more and more "useful" apps. I have no idea how often I update them.
Really. Where is the point if the agile development is so agile that there is one update a week?
The first rule I learned on a computer was to never change the running system. On my Android it is: If in doubt change the running system! Is the running system a question how ripe the system as such is?
I will keep complaining about the updates, but I will keep installing them, because I love to see the little changes in the software. What do you do?