He's absolutely right. The problem is that people buy their listeners some temporary comfort with their false modesty, but at the same time disempower them in the long term by saying that success is a function of luck.

Few people say their success was all luck, but many give it a bigger role than it deservers. It you are successful on a 10% play, it's easy to pass that off as luck. But if you made 10 plays like that, it's not really luck, now, is it?

Of course, sometimes the magnitude of the success is mostly luck.