Albert Einstein was also a gifted musician, playing both the piano and violin with exceptional skill. He once said: "The greatest scientists are artists as well." How can you argue with the man that has been arguable the most intelligent man in history. Our brain works in many fantastic ways.
Great scientists are also artists. Albert Einstein, one of the finest scientific minds of the 20th century was a gifted musician. In order to be a great scientist, you need to approach problems in new and creative ways, such as an artist would. Otherwise, there will not be new discoveries and progress will stall.
I believe that scientists are very creative people. The same with artists. Science is also an art. If scientists can create things in a "scientific" way they can channel their personal talents and apply them to art as well. Seems like through history, the people that made great advancements in one area were also great in others.
No, the greatest scientists are not artists as well. You do not have to be an artist to be a great scientist. There are many scientists who have no interest in the arts. In fact, it's a different side of the brain that you utilize to do math and science versus language and the arts. You can be a great scientist without liking art.