I think it depends on how it impacts the viewer and if the skill/craft supersedes the impact of the art. If it does, it almost becomes unnecessary, or maybe "unnecessary" is the wrong word, but it can take away from that impact of being moved by the art. It is then just more impressive than the impact or message. But beauty is always in the eye of the viewer, and that line between craft and art (if there needs to be one) is in them (the viewer). This is of course separate than the judgement on what is "good." Being moved by a work of art has nothing to do with that, but in my book, that is what makes a successful work of art.