“He writes his own songs. But you have to want to make rock and roll. And I don’t think David wanted it as much as I did. We all have to want the same thing..."
I wonder what David would say to that 
Thank you for the article.
I think David would agree, he didn't want to be a rock star but a songwriter himself, and as MK says in this interview, he achieved it.
Hey? How do you know that David would agree? Mark Knopfler has said on numerous occasions that he himself didn't particularly like the rock star part of being successful.
I was going to say the same thing. I never got the feeling that the fame you usually associate with R'n'R was something Mark really wanted. So it would not be surprising if David didn't, either.
That said, didn't Pick leave because he wanted to do a different style of music? That would also be the interpretation here, and not wanting to explore the same genre is fair enough. That's a more than justified excuse to leave a band.