The thing is the night of the long knives was an internal purge within the Nazi party focused on the Sturmabteilung (SA) which was the party's paramilitary force. The purge was outright popular with certain elements of society. The military didn't like the SA because SA leaders like Rohm were talking about replacing the German army with the SA, while German industrialists didn't like the working class background of the stormtroopers and saw them as threats to their interests. At the end of the day the SA's rhetoric about a "second revolution" wasn't terribly popular with German society.