My guess would be that Starfleet is continuing the age-old tradition started by NASA of NEVER WASHING THE EXTERIORS OF SPACECRAFT.
I've got this lovely shot as my desktop wallpaper; of the Space Shuttle Endeavour on top of it's 747 transport after arriving in LA prior to it's move to it's final resting place. There's all sorts of weathering in the form of brown and tan streaks and discolored areas. Probably from landings at Edwards dry lake and in New Mexico. Also some discoloration from rocket exhaust from launching. The Atlantis and Discovery were the same way. I saw a video of Atlantis after it arrived at it's permanent home at the Kennedy Space Center Visitors Center. They were power washing it and all of the brown and tan areas were washed away. It looked brand new and had lost some of it's character.
I guess Starfleet doesn't budget for starship washing.
I've got this lovely shot as my desktop wallpaper; of the Space Shuttle Endeavour on top of it's 747 transport after arriving in LA prior to it's move to it's final resting place. There's all sorts of weathering in the form of brown and tan streaks and discolored areas. Probably from landings at Edwards dry lake and in New Mexico. Also some discoloration from rocket exhaust from launching. The Atlantis and Discovery were the same way. I saw a video of Atlantis after it arrived at it's permanent home at the Kennedy Space Center Visitors Center. They were power washing it and all of the brown and tan areas were washed away. It looked brand new and had lost some of it's character.
I guess Starfleet doesn't budget for starship washing.