John Galt destroyed nothing except a room full of his own inventions. The railroads were destroyed due to the poor management of Dagny's brother (forget his name) and interference from Washington.
Also, from that link:
John Galt, outraged that anybody would even suggest that he or the company he worked for owed anything to the nation that provided his education, protected him from infectious disease outbreaks, protected him from Communist invasion, built the roads that got him to work each day, provided the police that kept him safe, and provided the court system that protected his property rights at all, sabotaged the Galt Engine, so nobody could have it.
As I recall, one of the heroic characters (Ragnar?) specifically states that these are all legitimate functions of the government and that they should be financed by taxes. In fact, one of the strikers actually worked for the government (Judge Narragansett).
It's always helpful to read a book before criticizing it.