Understanding a framework is a long and sometimes tough process. That's the only lesson to be learned.
The language PHP to the _framework_ Rails.
He didn't find the language (ruby) unsuitable, but rather the framework (rails) too heavy. This might of been exactly the same if he tried PHP with Zend/Symphony/etc.
His bottom line should of been: "Sometimes its better to work without a framework".
PHP has a lot of features built in which make it almost comparable to a framework. This is because it is designed for making websites out of the box, Ruby is not.
Coding in different languages definitely does make you look at coding from different perspectives, and you can often apply those lessons back to other languages.
PHP is an extremely powerful language for building websites and has come along way since it's original release, such as object-orientation, etc.
Admittedly, PHP has many flaws, such as poor error handling (for a newcomer, most veterans in this language know them off by hand and actually find them useful) and poor function naming, some are CamelCase, some are under_scored and some are illegiblyalloneword, but every language has flaws.
This is really the kind of cool-kid attitude which HN doesn't need, it shows a lack of due thought and that you have little to no experience of the language itself, if you had, your comment would have been. "This article was on HN 6 months ago, but, I believe that RoR is better than PHP for these reasons... " and not simple "PHP sucks."