Not going to argue with you that the field isn't broken -- it very clearly is -- but the problem the article explains is a rather simple one.

Your setting could be non-contractual. You might not be able to have reliable data to frame the problem as survival analysis with censored data. You might have different groups of customers with different behaviors.

Assuming a constant failure rate is the same as assuming the underlying process is Poisson, which is not an entirely stupid working hypothesis in many cases.

The moral of the story is "by the love of god look at your data before making dumb models".