I have to agree with you, I grew up building and growing everything we had... I really don't like letting others work on my things, and will just plain refuse it most of the time. I would definitely install the stud myself, but if he can't do it than he can't do it... For whatever reasonI guess my point is that there are some tasks that make sense for a gun owner to learn how to do themselves. Add the shipping expense to event he best "turn around" time and to me it makes no sense to send work like adding a sling stud out. Not when the cost of materials is less than that of the shipping alone.
On the other hand I keep forgetting that I grew up in an age when people weren't as afraid of tools like many in this current era. I guess that's why good gunsmiths are getting so busy and so many not so good gunsmiths are getting in the business.