A bad hire is not the end of the world, and is easily corrected and one can't help feeling there is some magnification going on somewhere about hiring mistakes. There is near constant evaluation and feedback loops in most organizations. A 'bad hire' simply won't survive this.
No ones hires a person not suited to the job in terms of technical requirements, that's a given, but there are other things at play to make the final decision, that are less easily obvious in the interview process so mistakes will be made. Better to make them and move on rather than manufacture this increasing hysterical narrative about the 'perfect hire'.