More from Leon and Amy Kass here:
To provide the same and new last name for the married couple, a name that proclaims their social unity and that will immediately confer social identity to their children, they could devise a hyphenated compound that both partners then adopt or they could jointly invent a totally new surname that leaves no trace of either family of origin. But these alternatives are both defective. The first is simply impractical beyond one or at most two generations; because of the exponential growth of life, one would have an exponential increase in names-to-be-hyphenated-in-new-marriages-and-in-newer-marriages-and-so-on-and-on-ad-infinitum. The structure of life itself makes impossible the universalizing of one’s maxim to add-and-hyphenate.