I would love more official scenarios with Hotels and Restaurants, but like Bo has said this week, its down to time and manpower. I am playing a wonderful scenario call Hurricane Hills which is rebuilding a theme park after a Hurricane. The amount of work the creator has done is incredible, this is well worth playing and is better than some of the Frontier ones.
Creating a good scenario would take at least around 100-200 hours, unless you a creating a very bland one.