(Hint: copying files to a server is not how real applications are deployed.)
The GP talked about "the given problem domains". One problem domain is simple, one-shot processing for plain old websites. Custom sign-up forms for stuff. Forms that email their data to some address. Homecooked personal-use search boxes that have "magic" functionality. All kinds of simple shit. These are deployed by FTP just fine.
Another problem domain is deploying something to virtually any cheap shared hosting provider. These very seldomly have e.g. ruby support. Sometimes, for all kinds of practical purposes, you don't get to choose.
At that point, it's equally easy to install a stack like haproxy + varnish + nginx + a bunch of CPAN modules as it is to rsync over a bunch of .php files, and therefore "it's easier to deploy" is meaningless. You click a button.
Not to pick on you specifically, but one argument that comes up quite frequently, especially in PHP vs. X discussions, is "I don't see how xxx feature of other language is beneficial." Well, the reason you "don't see" that is because you simply don't have enough experience yet. Deployment is the same way; a lot of people get by for years without ever "doing it right". But that doesn't mean the wrong way is right, it just means you haven't been required to get deployment right yet.
