There are many other devices locked down much more than iOS devices and this argument would apply to them as well. The only reason apple is the subject is because people want to take advantage of the massive, expensive engineering work that has happened over the past 15 years (in both hardware and software) without any of the limitations that go towards actually paying for that engineering effort (and enable many high-security use cases). If apple's product sucked and had horrible UX nobody would care.