As with most things, there is a compromise and a middle ground. Some people say "I never do set-ups and would far rather pay someone else to do it". Others say "That's daft, there are no special skills involved so do it yourself each and every time".
My view is that both are wrong (for me). I do[i] most[/i] of my own set-ups, but sometimes there is an issue that I can't (or won't) deal with. Then I call in the Bass Doc!
I don't understand why people are arguing over such a trivial thing. If you wanna do it, do it. If not, don't.
But I do agree with the OP that a "standard" set-up is a straightforward job that doesn't take much longer than changing a set of strings (unless you've got a headless Status, in which case changing strings takes seconds!).