I can see how this might be useful as a slightly more intuitive alternative to stock photography, where there is a bit more of a say as to what the composition is made up of.
Maybe for a graphic designer wanting a quick result for an idea.
Personally i don't see any potential for matte painting. I think only technical processes benefit from some automation, such as rigging for example, where there are plenty of rig builders available for an animator or modeller who isn't interested in a complex, custom solution for their character and just wants to animate.
I can't see how a highly artistic process such as painting could possibly benefit from being replicated by a script, even for an initial rough composite.
The key part for me is that i wouldn't trust an algorithm over my own eye to get better results for source material searching.