To be fair to Paul, here is a bit more of the context:
Code size is important, because the time it takes to write a program depends mostly on its length. If your program would be three times as long in another language, it will take three times as long to write-- and you can't get around this by hiring more people, because beyond a certain size new hires are actually a net lose. Fred Brooks described this phenomenon in his famous book The Mythical Man-Month, and everything I've seen has tended to confirm what he said
So which credibility are you doubting, Paul's or Fred's?
"Never try to teach a pig to sing…it wastes your time and it annoys the pig."