"They didn't invent the concept of the PC"
Oh quite the opposite. They did exactly that. The Apple ][ was the very first PC. What you think of a PC was scrambled together by IBM with leftovers in a hurry when they saw the wild success of the Apple ][. Apple ][ was released in 1977. 3 years before the IBM PC.
Olivetti beat Apple by 13 years with their Programma 101 in 1964.
", nor did they invent the GUI. "
They did indeed invent the modern, working GUI. The concept they bought from Xerox was not completely developed and lacked many key features. It was not really usable. The first usable GUI computer was indeed the Macintosh in 1984 when all others used CLI.
You're contradicting yourself here. The PARC user interface was invented by Xerox. All Apple did was innovate.
"Truth be told, Apple has never created a completely new and untested product from scratch and been successful with it. "
Wrong. Just plain wrong. Your bias and lack of knowledge is showing.
I hate to bring it to you, but he's right. Every single successful Apple product was an innovation of an already existing product, not an invention. If you're so sure, I'm sure you can name one Apple invention that has been successful.
"Also, marketing. They have really good marketing."
Their marketing budget is tiny compared to MS or Samsung.
He was talking quality, not quantity. It was a compliment.