> boiled down to "I cannot put even a minimal effort in keeping an eye on my children, so I will blame someone else for it and make it their responsibility."

When you add multiple devices/platforms/app stores it becomes a lot more difficult. Sure it is a relatively seamless experience on one platform, but not all of them. Additionally, parents who didn't grow up with cellphones don't even think about this stuff until it happens. It isn't common sense for them.