the point is that I am usually doing all the stuff in my scenes for myself. From textures, over materials, models, atmospheres and so on. And many others do this too.
Just take a look at archviz - there are awesome renders, but in many cases the design came from an architect. The textures come from dvd collections or sources like cgtextures. The plants in almost all cases are stockmodels from xfrog, evermotion and the like. The furniture and other decoration also mostly is stock models.
So the artist "only" threw together the stuff and does a nice rendering from that. So where is the difference to artists in Terragen who use stockmodels?
If you dare to put a poser figure in an archviz scene, you will get many bad comments, no matter how nicely the scene is. But no one complains, when you use a car from Dosch, textures from Arroway, HDRI backdrops from Sachform or trees from Xfrog.
A lot of people simply don´t judge fair. If they read Terragen, Vue or the like, then the picture is nothing worth anymore. They don´t take a look at how much work went into such pictures, they don´t care how nice a picture might look. It´s just something like "oh, Terragen - yes, okay, but TG is made to do nice landscapes". Well, Autocad and max are made to do nice archviz...