The Renaissance is for many, the zenith of artistic expression in western art. For those who feel this way, there are some pretty good arguments for support. It is undeniable that some great artists lived and worked during the Renaissance. You would be hard pressed to find someone that would argue that Leonardo da Vinci, Michelangelo and Raphael were hacks. There were also important technical advancements. Perspective for example, became more of a science and spatial relationships in paintings became, in some cases, very believable. Artists began studying anatomy and learning about not only the surface of the human body, but also about its structure. Art during this time contained elements of realism and passion that people responded to and continue to respond to even today. Art during the Renaissance was big, bold and everywhere. Painting and sculpture during this time was important to people. In some ways it was the heyday for painting and sculpture. While I am not about to argue that painting and sculpture are dead, I do not believe they hold the same place in society that they did in the Renaissance and perhaps that is part of the reason why people who love art look back to that time.
All that being said; is it good for art if Renaissance art remains the dominate aesthetic? While, as with all fields of study, it is important to learn where you came from, it is not healthy to stay fixed there. While there is certainly a place for people who wish to continue with the ideals of the Renaissance, there also needs to be forward movement if art is to stay vital.