The "key dance" to pull codes in my 01 Cruiser is pretty cool.
That said, I still own 3 code readers/scanners. The latest iteration reads everything, real time, records, runs a limited few tests, is much faster, and also reads ABS. And yes, I have one in my Cruiser, my newest with me in the LeSabre, and my sister, who lives about an hour and a half away has the one that just reads fault codes, so I can help from a distance instead of driving all the way up there.

But, I think some people just don't know what to do with a code, how it impacts the system, or how serious something really is. You can't design a system for the small % that know what to do with the information. Those that do know, most likely already have scanners, know someone with one, or a place that will scan it for free.

Its almost like having access to medical test results. A good doctor will know what results mean, and be able to help. But give the same info to someone who only has access to WebMD, and they start diagnosing themselves instead of seeing a doctor, they may end up in worse trouble.