Art is very personal to an artist. Not everyone has the same taste, viewpoint or liking than anyone else. One may like some type of art, style, colors, ethnicity etc, while disliking anther, and one is free to say so, but anyone should keep in mind that there is an individual at the other end of the artwork, and that individual experiences emotions and feelings like any other human being and one should think twice before expressing a comment that could hurt one's emotions, feelings and ambitions. 

An artist also has full legal copyright of his own original creations, therefore, while it seems easy and ok to just copy a picture to save some, remember that that is lost money for the artist and it can cause that artist to stop being able to produce more artworks because of this. On top of being an illegal act.