Cost, mainly. Plus it would require a whole new section of the factory with additional workers and equipment. Historically, Scamp tried to keep their operation lean and efficient to keep costs down and weather downturns in the highly cyclical RV market.
None of the major molded fiberglass manufacturers paint their trailers. Tinted gelcoat is the industry standard. Relic (a small volume boutique builder) is one that does, but I’m thinking they may have to because of the way their complex one-piece shell is molded.
From my point of view in Arizona, paint- especially a dark color like green- won’t last as long as gelcoat, and repainting is very expensive.
For an inexpensive, like-new shine on your Scamp with less work, you might want to search old threads about the use of Zep High Gloss Floor Wax instead of regular automotive or marine waxes. I’m thinking about switching over on our 2008 for the next round.