From memory, there is a History of Programming Languages book from an ACM conference that contains some papers that were presented there, along with some notes from Q&A sessions that followed. I'm paraphrasing, but Dennis Ritchie said something flattering about Pascal, that it was essentially the same language as C. Given this, asked Niklaus Wirth, why do you suppose that C is so much more popular than Pascal? Ritchie answered, "I don't know".
My personal opinion is that Ken Thompson is not given enough credit for the beauty and expressiveness of C, as much of this comes from its predecessor, B, which is essentially Thompson's "remix" of BCPL.