I've always enjoyed learning about how things work...
From the first time that I experienced a reg issue which threatened cancellation of one of my dives, I realized the value of knowing how a reg works and how to do some simple on-the-spot troubleshooting. When I began shopping around for my first reg, in the back of my mind I had the thought that one day I wanted to go down the DIY-servicing route. Since then, one of the factors that I always consider in a reg purchase is how easy the reg is to service. I currently service my own regs. I didn't mind investing time and money into learning how to service my regs because, even if I never picked up another reg tool, I would be in a better position to double-check the work of the reg tech I paid to do the job.
Someone in the DIY forum remarked that, when it comes to regulator servicing, a talented child could do it. While that perhaps overstates the simplicity of the task, it's not very far from the truth.
I think that all regulator owners, as part of the reg purchase at their LDS, should have the opportunity to learn: (1) how to do a comprehensive functional reg check, (2) how to tune their 2nd stages, and (3) how to check the i.p. on the first stage periodically. Basic OW instructors aren't teaching divers how to do proper reg checks, so I would hope that divers could learn it somewhere. Regs purchased online (a more common occurrence in recent years) should come with detailed instructions on how to do all of these things. Divers shouldn't treat their regs as magical "black boxes" that deliver breathing gas.
In many ways, DIY reg servicing can be viewed as a natural path for an assertive diver interested in making the sport safer.
I say all of this knowing that there are lots of divers out there who lack the interest/time/temperament necessary for DIY reg servicing. That's perfectly OK, too. This just means they'll have to rely heavily on a local reg tech and may have to sit out a dive or two at some point. Not a big deal really.