This is why I take my cars to a small independent shop. He's not any cheaper for the work he does, but I don't have to deal with a "service advisor," i.e., high pressure salesman, and all of the other theatrics. Also, if something can be fixed and not replaced, he fixes it. For instance he fixed a stripped thread instead if replacing half of the car. I've experienced the high pressure sales tricks, and my spouse has experienced how car shops treat women. Part of the schtick was to scare you into believing that a car needs extensive maintenance to remain roadworthy. But it's not 1975 any more.
On the other hand... people keep going to the dealers for service. I assume that there are enough people who
actually like the checklists, ceremonies, and so forth, to keep the dealer service departments doing business the same way. There is also a customer base who
absolutely wants to never have to open the hood or even think about the innards of the car, and the same is true of bikes as well.
It could be that Trek is trying to emulate that atmosphere, to attract that customer base, who are happy with it. But the devil's in the details. Making multiple trips and multiple phone calls is just too much for servicing something as simple as a bike. Trek is the new Schwinn. I'm not saying this in a bad way. This is what you expected when you bought from Schwinn in the 1960's -- you would be completely taken care of, with Schwinn service and Schwinn approved parts, for a price.
Going with what
Moe Zhoost says, it's true that a cyclist should be able to do this kind of tune-up themselves, but I would go even one step further. I don't do a scheduled or checklisted tune-up at all. Instead, I'm attentive to the condition of my bikes when I ride them, and take care of adjustments as needed. If the bearings are working fine, I don't mess with them. I tell people that the overall experience of cycling can be greatly improved by gaining some self-sufficiency on basic maintenance.