Not many people would take issue with the statement that Shakespeare was 10x better / more effective than the average playwright. If you consider that both are creative processes there seems no reason to reject the idea that a programmer could be 10x more effective than his peers.
The comparison between writing a play or a program starts to break down if the problem space is narrow, as the article also mentions, so a lot of what people end up arguing about is what programming actually is.
If publishers decided they were only going to publish Shakespeares, I imagine a multitude of authors would squander a great deal of ink over it, and we'd all be worse off for the cumulative waste of talent.
The comparison between writing a play or a program starts to break down if the problem space is narrow, as the article also mentions, so a lot of what people end up arguing about is what programming actually is.