I actually don’t think this has anything to do with standing up for their users but is a simple cost/benefit analysis: building compromised E2E-communication that is still reasonably secure against bad actors is much more difficult (if not impossible) than building robust E2E-communication. Apple just doesn’t want to lose business users over headlines like „iOS messaging used by Chinese spies to steal US trade secrets“, while headlines about how difficult it is for government agencies to unlock iPhones probably drive sales. Nothing morally or ethical here, only profits.