I agree with you, I think the sketchup´s ruby console and the 3dwarehouse makes the difference among other free and more powerful 3d modelers like blend.
The sketchup became a universal tool and library of models beyond the google brand, Trimble brand because of the 3d warehouse/ruby console. The sketchup tool itself is only a simple and unattractive tool for professionals.
And they only have so many 3d models because of sketchup make and the thousand of teenagers, children, personal users and self employed architects designers .
The companies that earn contributing to the 3dwarehouse are companies of furniture, lighting, etc because 3dwarehouse is a free advertising site. And the best models are usually downloaded and bought physically.
The clients usually wants the same furniture(the beaultiful ones) they saw in sketchup model.
The people off Trimble can make a effort and think other ways to make profit, as WhatsApp, facebook, google, etc estimulating a social network with models, to turn it self sustainable.
They can’t´t see that the money isn’t in the sketchup but in the 3dwarehouse. Many people would pay for a model of a new car, furniture, if it costs cents, like music in the iTunes or monthly, like Spotify.
sorry about my English(with the help of FREE google translator).