...No one should feel bad if based on a real knowledge of what it takes they decine to do their own regs and take them to someone else. I'm quite capable of doing my own automobile brakes, but I tend to take them to someone else.
They key is not to be scared into doing so by folks who want to take your money. Hire others to do it if you don't want to, or if yoiu fell you can't, and do not be ashamed of doing so. But don't do it because you've been scared you into services that really are not needed done by people who are likely not much more capable than you are....
People hire other people for a combination of one or two reasons.
They prefer and can afford (both the time and the money) to have something done by someone else.
They have no idea how to do it themselves and prefer to trust a professional.
I do my own servicing, on most everything I own. However, I don't do my own surgeries or mix my own pharmaceuticals. Regulator service is very easy for me but may not be to someone else. For those, like DivingPrincessE, she is smart enough to know that having it serviced by a professional is the right choice for her, despite her dive vs post ratio.