AUSTIN, Texas -- Google+ has been called a "ghost town," a "little version of Facebook" and "dead" since its launch last year. Users have continually questioned what it is and why they would want to use it.Google's senior vice president of social business, Vic Gundotra, attempted to rebut critics' claims during a panel at South by Southwest on Friday and defended Google+ against allegations that users are fleeing a stagnant service.