WIKI
According to Albert Speer, “the Right, represented by the President, the Minister of Justice, and the generals, lined up behind Hitler ... the strong left wing of the party, represented chiefly by the SA, was eliminated.”
https://en.wikipedia.org/wiki/Night_of_the_Long_Knives
Hitler knew he needed the industrialists to build the war machine. Once the war was over, and they were no longer needed, they would have suffered the same fate as their Jewish victims.