You haven't worked on a late model car before.
You can turn systems on an off to troubleshoot them. Before, you could do this mechanically. Now, you have to use a computer.
Setting the speedometer is pretty common when a tire size is changed.
Setting the odometer can usually only be done once each time you replace the instrument cluster.
All I know, as someone that still likes to turn their own wrenches, is that I don't want more security on the only way I can still work on my own car. If they lock me out of the diagnostics port, I won't buy the car.