content: That's not entirely true, you CAN sideload uwp apps, but  a. Why would you want to? b. Its off by default, and the option is buried pretty deep. The average user won't change that setting, and it has apocalyptic warnings of viruses when you try to disable it, even though a rouge x86 app can do just as much (or actually more) damage. c. Who's to say MS doesn't remove this ability later.