If the program fails too often or too unfairly, why should you blame how such failures are handled? The only reasonable "probabilistic estimation" is that something that happens 10% of the time is normal and it shouldn't be treated as an "exception", even if actually thrown exceptions were fast.

> If the program fails too often or too unfairly, why should you blame how such failures are handled?

Because the discussion is about methods of reporting and handling failure?

> The only reasonable "probabilistic estimation" is that something that happens 10% of the time is normal and it shouldn't be treated as an "exception"

That makes no sense whatsoever, and doesn't address the question.

And even if a ctor fails at a rate of 0.9, it has to report errors via exceptions, because that's the only mechanism available to ctors.

You could use an output pointer parameter. You could construct an object which self-reports as invalid. You could take an error handler callback. You could use a global variable.

Or I think my preference would be a private constructor, and a friend-function that returns value-or-error.

Adding to that once exceptions start being thrown, that ratio changes because the cost is so high. It's not hard for a service to reach a failure rate just high enough that it overwhelms the system.