I'll always support user choice and that is the only thing Apple will be forced to allow. It's extremely bizarre to justify vendor lock-in on the basis of popularity.
Imagine if Microsoft would prohibit you from using Google search on Microsoft devices and force you to use Bing and anyone would justify this on the basis that Bing is unpopular.
Imagine if Microsoft would prohibit you from using Google search on Microsoft devices and force you to use Bing and anyone would justify this on the basis that Bing is unpopular.