No it’s not. You can study history and strive to understand the truth of the matter however imperfect, perhaps across various perspectives and with appropriate deference to contemporaneous context and the roles of the players in arc of global history, or you can see it as a means to an end and select and present so as to advance the narrative that you feel bests moves mankind to wherever you feel he need be moved. I’ve nothing against Zinn - dude wrote a book. Whatever blame for whatever fault there might be lays at the feet of an education establishment who selected his narrative as the one with which to indoctrinate a generation of Americans.