Whether or not you start learning PHP or Rails or JavaScript, or
whatever else, is irrelevant. Why? Because making the switch from one
language to another is incredibly insignificant compared to making the leap from not being a web developer to then being a web developer.
That issue comes up when you ask for help and someone chimes in with the belief that in order to receive the correct kind of help, a certain approximation needs to be established that determines the mediums used to fulfill requirements, hence the constant topics of languages, etc. That always comes up when someone coming into the field(s) inquires about what they need to learn: the common response I always see others reply with is, “Well, what do you want to do?” (Which incites the language dialogue because most enterprise shops have traditionally used a specific set of technologies whereby those not considered enterprise would use others – as an example, I mean.)
I think I get what you’re trying to explain there and it makes sense… It’s just that the initial baby steps someone takes when trying to become whatever a “web developer” is anymore is monumentally defined by what exactly said steps consist of and due to how these fields are, everything boils down to specifics.
(And don’t take that in any specific way – it was just something that came to my mind when I read that part of the article, which was great, btw. 
)