FACT: Mechanics don’t like to clean your bike, but like that you don’t either.
If you privately ask a bicycle mechanic which part of a service they don’t enjoy, they will more than likely answer “cleaning someone else’s bike”. A mechanic just wants to fix your bike and fit new shiny stuff! This is why some bike shops add an additional cleaning charge to the service.
However, there is a flip side to this – a bicycle mechanic loves that you don’t clean your bike either, as improper cleaning can actually lead to more damage, mainly to bearings. Using a pressure washer or hose pipe to clean your bike generates enough force that washes dirt into the bearing, once there that dirt will accelerate the brinelling process. If you want to clean your bike, wait until all new dirt/mud has dried. Brush any loose bits off and use baby wipes to clean the frame.