I broadly disagree, although I see where you are coming from. The reason is that I've found coding useful in every non-coding job I've had where I have sat in front of a computer in an office... Office jobs, and general running of any business can be improved with knowledge of code - as well as code itself imo. The understanding of how to define procedures explicitly is great - although humans are error prone I've worked with enough broken procedures to know that the vast amount of errors I seem to encounter when dealing with... everyone, could be reduced with some good practice.

I have to say the best results I've gotten from (usability) testing is sitting down/chatting online whilst the most stupid (I hate that word, but it is the only accurate one) of users try to use my app and helping them through it so that they can keep hitting the UI snags and even turn up some bugs that everyone else was just too sensible to ever trigger. The stupid users tend to get stuck in many places and reveal whole piles of issues very quickly, whereas regular users tend to avoid the more common mistakes and adapt more quickly to your new ones. Whilst I tend to know about problems that "regular" users pick up on before they even report them, I'm often surprised by the things the "idiots" try. Things so silly that, without my realising, I implicitly assumed users would not try to do them, whilst writing the code/designing the interface. I've never released software with an intended audience of larger than a few hundred users, so I guess that if you have a big enough user base this might do itself through support e-mails etc.