According to www.dictionary.com an artist is someone whose work exhibits exceptional skill.
This same site defines craftsman as a person who practices or is highly skilled in a craft; artisan.
And their definition of art is "the quality, production, expression, or realm, according to aesthetic principles of what is beautiful, appealing or of more than ordinary significance."
In my opinion, someone just learning how to quilt, would not be considered an artist, as they are just learning. They are a novice. They need to hone their skills to become an artist. Just sewing pieces of fabric together, does not mean someone is an artist. Just like someone that does "paint by number" is not considered a painter. There needs to be some skill involved to become an artist no matter what medium you choose to use.
Ages ago, people had to apprentice with a master craftsman in order to gain the skill necessary to be called an artisan. And I believe that same holds true today, while we may not have traditional apprenticeships, we take classes and use other forms of teaching ourselves how to quilt, and how to be better at it. This isn't to say that those just learning aren't or can not become artisans, but there needs to be some skill involved. Just the act of sewing fabric together does not constitute art, unless there is some skill exhibited in the final product.