This post is a rhetorical rant, so it's best not to take the core premise too seriously. Even though the title is "Ruby is faster than Python, PHP, and Perl", I don't think it's the author's intention to make that broad claim. Rather, the intention is to beat out of everyone's head that Ruby is "slow".

When speaking about languages in the same ballpark (Ruby, Python, Perl, etc), it's difficult to make blanket statements about which one is "faster", because they each have their warts. Depending upon what your application needs to do, you may run in to those warts.