Of course, that's assuming that it fails safe - i.e. the failure mode is that it's bricked. If it fails by inaccurately calculating a deco obligation, you might not realize it had failed until you got bent.
However, I agree with you. At some point we are putting our lives, or maybe just our health, in the hands of some piece of hardware and software (unless we are diving tables and square profiles on a site with known depth). One of the benefits of understanding deco better and planning ahead of time is that you may have a sanity check on what the DC is telling you if you are getting a wildly inaccurate NDL.
But I suspect that some of the people who are suspicious of the Apple and Oceanic partnership wouldn't have a problem going to a dive resort and renting an aging, off-brand DC from the shop and trusting that.