Very interesting. I think you're probably on to something about the popularity of wordpress driving the language adoption - purely judging by the number of jobs I see advertised that specify wordpress experience.
However, I don't think that google keyword search analysis can show a preference for wordpress over other code frameworks. It only shows that people are more likely to be searching for those keywords.
Developers tend to google for things they want to know about, and don't have info on-hand. They won't google for a well-documented framework that is clear, "pure" and simple to use.
At that point, it's likely that either they won't be experienced enough at coding to know what a framework is (and therefore won't be googling it) or they'll be comfortable enough with looking at the code, reading the supplied documents, and the like - that they won't need to do many searches.
I've been using codeigniter for 2 1/2 years on my current full-time project, but I don't think I've googled for that keyword even once. I don't need to - it's well written, consistent, and follows known design patterns.
Also, wordpress is used as a starting point for people who want a "quick site" and then want to expand it. Those developers are much more likely to be googling to find out what the "next step" is.
Manuel Lemos - 2013-07-31 04:39:29 - In reply to message 1 from Anthony Demetriou
The way I see it people do not search Google just when they are looking for documentation. Sometimes they just want to go to the project site and use the browser search box as a shortcut to type the site full address.
According to Google people, there are even many users searching for the Google home page using Google. It may sound odd, but those are users that are searching in their browser search box.
That said, I do not think it is not just like WordPress users that search for WordPress and framework users search less for the framework names.