The problem that I have with Apple's defense of their walled garden, is they act as if it's either you are totally secure behind it (not true) or if they allow

The problem that I have with Apple's defense of their walled garden, is they act as if it's either you are totally secure behind it (not true) or if they allow sideloading then there can be no security or the worse is going to happen. Sideloading would be optional, thus not all users will use it. The more likely to use sideloading, would be the more tech savvy or more willing to take risks. So it's more on those users for taking the risk. It's not like everybody is all of the sudden going to do sideloading, if it becomes available, and especially if they are warned about the risks involved. There is also a lot that Apple can do to increase security, despite the usage of sideloading. Among such measures, they could show all permissions and rights that an application wants, to include allowing users to block various permissions or applications attempting to use such.