True; although, both have a place in the conversation.
Dale Carnegie = Marketeer
-He authored the bestseller: "How to Win Friends and Influence People". The book continues to sell today even though it was first published in 1934. I'd recommend it even to non-Marketeers.
Andrew Carnegie = Business Guy
-He's remembered as a Business guy for doing titanic mergers and acquisitions in the Steel industry. However he did not come from a wealthy family and started his first steel company from the ground up.