As we have seen in most aspects of Celtic endeavor, many critics consider anything associated with the Celtic tradition to be inferior. Roman and Greek critics, for instance, found Celtic Art/Craftsmanship to be inferior. However the surviving artifacts belie the criticism. Celtic art/craftsmanship was equal to or superior to those of any comparable society...including Greek and Roman.
All one needs to do to confirm this observation is to examine the surviving artifacts. The designs created by the early Celts are extremely intricate and interesting. These very same designs are used in numerous applications today (Celtic Knots in jewelry, on tee shirts, in tapestries, swords, and so forth). One can observe such craftsmanship and artistic touches in the numerous coins that survive from various Celtic eras.
In brief, it seems absurd to find fault with Celtic craftsmanship/artistic talent when the evidence of their talent is obvious in all the artifacts that survive from early Celtic times. I have provided but one visual of early Celtic art above but it seems sufficient to make the point. The above visuals are of the Gundestrup Cauldron, which is indisputably of Celtic origin. It depicts various aspects of Celtic belief in quite well done reliefs requiring considerable artistic talent. The existence of the cauldron shows such things could be made giving evidence to craftsmanship. I urge you to look at other Celtic artifacts and judge for yourself whether the work is "of quality". You can find some illustrations of the Celts work by following this link.