As tempting as it is to criticize Apple for being some evil empire, another highly plausible explanation is simply that their products are quite good, and people are willing to join the ecosystem for some inconveniences / loss of freedom. And the side point that not everyone (though it might seem here) is a 20 year old hacker demanding that they be allowed to jailbreak their phone, or insisting that all WhatsApp chats be able to integrate with iMessage as a matter of moral principle.