Literally the only thing that PHP has over Ruby/Python/whatever is ease of deployment. It is ridiculously easy to deploy a PHP application, whereas you will jump through a lot of hoops with other solutions.
After a lot of thought, I've arrived at the conclusion that this is because PHP has its request handler and template language all baked into the same process. It's pretty great at that - no setup required to start slinging code.
Other than that (which is significant), I'm hard-pressed to find an advantage. It's verbose, inconsistent, lacks features that've been present in other languages for years, and as the article author complains about, has no real vibrant packaging system for leveraging code re-use. Code re-use in PHP is "copy-and-paste". Yikes.