Hi Jasman, you're right, and Allan has written a paper for the Australian Mechanics/Engineers journal. I gave my copy to the proud new owners of my Jeep as a guide, but someone here may have a copy or it might be searchable via Google.
The basic premise is that modern diesels with a DPF filter must have a good long hot run regularly to burn out the carbon build up in the filter. If it clogs up some serious damage could be done to the engine, turbo etc. I'm not a mechanic so someone will be able to be more techie than me on this.
If you are a city dweller with a modern Diesel engine, the daily run to school, shops, work etc aren't considered effective or hot enough to burn it away and it's a case of 'Danger Will Robinson' if you own one.
As you said, this is not just a Jeep thing, this applies to a lot of modern Diesel engines. I have read a thread here on this lately.
It's a Narvara STX V6 TD 3.0L