Warning: the following reply may be somewhat acerbic due to real-world experience on both ends of the interviewing table.
That's only because those who haven't been through a PhD program are ignorant as to the amount of intense work, self-motivation, and ingenuity a PhD requires.
As someone who's been through a PhD program and dropped out in disgust, and has subsequently interviewed quite a few PhDs for industry jobs: baloney, it's pretty much as the GP describes in a great number of places. It's a highly-politicised who-do-you-know academic circlejerk. And PhD work is usually nowhere near as "intense" as proper high-level real-world work anyway (something a lot of them learn to their detriment in the first few months on the job).
Many PhDs have already worked extensively in industry.
Whoa, hold on there, now we're not just talking about PhDs, we're talking about PhDs with actual real world experience. That's a much smaller subset than you imply, and quite a few of that subset had *failed* real world experience that made them go back to PhDs. Someone with a PhD who's made it work in the real world is extremely valuable, because at that point you actually have evidence that you really have found that smart, motivated, ingenuous person with serious specialization who can be forgiven for naively believing the academic fairy-story that a PhD would actually be valuable outside of the world of academia.
The less you know, the less you realize how much you don't know.