So, either people are painfully stupid or a managed platform has some appeal over free ones.
Continuity, ease of use, various warranties/guarantees make walled gardens attractive. If consumers have free reign and brick their device, it's hard to expect the manufacturer to have/honor any warranty. If developers have free reign there's no guarantee another application won't break theirs or that they won't break someone else's... or that it'll work with whatever the consumer is doing.
Yes, an obvious counter point is *nix systems, but there is some authority in that ecosystem which keeps most things working. It's still not painless to setup/use which prevents it from effectively competing with windows/Mac OS.
Simply put, the price of admission into a walled garden comes with some perks/guarantees/warranties which aren't readily available elsewhere.