[ceejay]

I agree there are very few people who know PHP well enough to build large web apps with it. On the same token I doubt, once you get that big to where it really matters, there are many web devs who know how to write web apps that scale well at all.

Everyone else is just taking advantage of a few milliseconds here and there (for example compiled language vs interpreted language) that might "appear" the language is better suited to the task, but ultimately only are as good as the architect(s) of the system made them.

I disagree PHP the language is deficient in any significant way that would prevent anyone from building large, modern web apps with it.