Programmers of popular programming languages

Hmm... as some of you probably know, I collect exotic programming languages. This quote made me think:

If you program in the most popular programming language, your skill in that particular language is a commodity. If you program only in the most popular programming language, you have made yourself a commodity. A commodity can only compete on location and price, and location doesn't really get you much on the Internet. This means that only people with a poor understanding of economics program in PHP.

Lifted from http://gilesbowkett.blogspot.com/2009/01/why-hacker-news-thinks-php-won.html

What do you think?