This is the core of the issue. What level of service are you paying for. More to the point, what's called for on your bike. For most fair weather riders who don't ride in the winter, or rack up many miles, a tune up is all that's called for, and may even be more than necessary.

Those who ride in all weather conditions, especially winter riders, should probably do an overhaul, where salt and grit is cleaned from the bearings. best time for the overhaul in in the Spring, so you start the season fresh.