It cant be disputed that making a game does take time, patience and of course funds. But as a benefit, would it be good if a demo release would be available? A one standard route. Nothing fancy.
The benefit of this would be on having constructive feedback, although I agree some feedback would be a bit far fetched, and if OMSI will have the option of personal "ad-dons", members would have the opportunity to insert their 3d created bus in the game, test it, and if the model is a success, pass it along to the OMSI team to try to implement it in the game saving them some sort of amount of time.
This would not only be for buses, but for structures, trees, bushes, an additional variety of cars etc...
Just an idea.