The term "Artist" is referring to the profession.
Best way to describe this train of thought:
If I were to draw the plans to a house, would that make me an architect? I could potentially be good at drawing plans, but that doesn't make me an architect. To become an architect one must be trained and possess the knowledge to do their job properly. An artist is someone who is trained and has completed said training. Now the best way of proving that you have this training is to have a degree, otherwise you will have to of gathered sufficient experience. There are very few professional artists in history that were not trained by an artist or didn't go to an art school.
You can be artistic, but that does not make you an artist. You can be creative, but again, that does not make you an artist. I suppose the best way to understand art and to understand what makes an artist is to take up critical theory in art schools. Art is highly critical and requires a lot of thought and discipline to understand it.
I'd consider myself a student of fine art. (Fine art is more specific than Art, but I'll leave that debate to one side). I'm being trained in traditional print making and traditional painting by some of the finest artists in my country. While difficult, I have come to appreciate it more. I feel that you have to earn the title "artist" as it is not something you are entitled to.
I suppose the best advice is that it isn't about the end product. How on arrives at the end product is what makes the piece.
An example would be an artist I know that was making steel origami. He said that he has never in his life been able to figure out how to make a swan. The piece technically failed, as it did not turn out perfect, but he did get his point across if you ask me. Your end product can fail but some sort of process has to be present for that end product to be valid.