As a certified Apple technician who does this for a living I can tell you that this method both works & is literally recommended by Apple in their technician training.

I agree it very often can be the first indication of a larger problem and that warning is definitely something I tell my clients and should have included here. But it is not worthy of your opening sentence implying I just recommended something horribly wrong.

If a system is under warranty then fine, ask an AASP or Genius Bar to replace the drive. But very often you have scenarios when a system is not under warranty and the user (or reader of this forum) does not want to spend the money on a new drive and would like to try all options available. Zeroing out is a viable option that can have good results.