I've always believed the demands on a bike shop, and the demands on a home shop may well be different.
Take your bike into a shop for a tune-up, and what will they do? Adjust the derailleurs, and perhaps check the cones?
That same bike tuneup at home might involve taking every bearing out, cleaning, repacking, etc. Truing the wheels. One quickly ends up with a day's worth of work, perhaps more.
I was in a bike shop once when someone brought in a bike with damaged rusted spokes. The only solution the shop gave was to replace the wheels. I'd have just bought new spokes and rebuilt the wheels. Oh, and of course also repacked or replaced all the bearings.
Different demands based on different environments.