I think he doesn't like all the upvotes for the snarky anti-PHP comment:

You don't really learn PHP so much as catch it. Like a disease.

At the risk of being modded down, the comment has some merit. PHP programmers usually gravitate to PHP without having much experience with related, but supposedly better, languages like Ruby, Python, Lua, etc. But PHP programmers who really dig into programming often leave for other languages. The Ruby and Python communities are full of ex-PHPers. But how many people from the Python or Ruby communities leave for PHP?

This isn't to say that PHP has no merit. It was my first web programming language. But maybe its merits don't stack up well against other languages, which is the subject of the original article.