Well, but if most maths PhDs don't end up in mathematics, then wouldn't a good industry job be an aim of a maths PhD?
If I recall ParticleGrl's posts, her PhD experience was very different from homeomorphic's, in that she enjoyed it. What was common to both of their experiences is the good industry job took a long time to find, though it seems both managed to find one after a year or more. I am not sure I am representing her correctly, but her initial posts had reservations about doing a physics PhD because of the difficulty of the job search, but her later posts indicated that she would recommend a physics PhD but to be prepared for a very difficult job search.