GIMP, Inkscape, Blender and other open source art production tools have a big chicken and egg problem. To really improve, they need more professionals using them and a part of them should be developers or willing to chip in by other means. But because there are issues (education included) that are deal breakers for pros, you can't expect it to get better quickly. The situation is much worse for art production tools (than e.g. programmers' tools), because a smaller portion of professionals in the field are also capable programmers.

This is a pretty sad situation and I can't how it would change, apart from giant (in open source terms) donations that would allow a developer-year or few full-time.