Concept artists are satellites of the art director. Along with any other artist on the project. Businesses are modular. Instead of trotting all the concept, 3D, texture, animation, lighting, and other artists into a meeting with the director; you just send the art director. The art director transmits the needs of the project to the artists who crank out ideas. The art director is in charge of making sure the ideas used meet the requirements of the project in both subject, quality, and style. And I do believe art directors still make art too in some capacity.
A concept artist responds to a prompt. He works to the needs of the art director. The interpersonal skills come into play when the concept artists work amongst themselves and other branches of the art department. For example, in the game industry, you may have a 3D guy come to you with questions about a concept. Plus departments have meetings comprised of themselves and the director/producers to monitor progress. As both concept artist and art director, you work on a team.
"Astronomy offers an aesthetic indulgence not duplicated in any other field. This is not an academic or hypothetical attraction and should require no apologies, for the beauty to be found in the skies has been universally appreciated for unrecorded centuries."