Marinetti was also the author of the Futurist Manifesto. The Fascist Manifesto that he co-authored advocates an ideology that is quite different than that practiced by fascist Italy and especially fascist Germany, so was arguably not advocating fascism as we know it today. He also opposed the anti-Jewish racial laws of 1938.

His futurist political beliefs were ultimately silly IMHO, but I don't think it's fair to cast anyone who quotes his futurist writings as a fascist, let alone casting the entire movement in which the person who quoted him plays some prominent role as fascist.