Please don't blame R for the ggplot syntax -- it is bizarre on its own. Also ggplot requires very specific form of input, and thus many scripts must be heavily polluted with a nontrivial preprocessing routines.
Obviously the situation is opposite when one considers, let's say, "analysts", i.e. people that expect to be able to completely ignore the form of the data and focus purely on the content -- for them your stack of tools is a pure gold, even with its trade-offs.
Some clarification about what you mean regarding efficiency would be useful - do you prefer arrays?
Maybe I'm alone in that, but I believe the power of R lies in its resilience and the fact that it allows me to write code that is equally obvious in what it does as how it does. The philosophies of one-true-data-structure and natural-language-like expressions doesn't play well with it, though I admit they are very useful for people accustomed to a declarative programming.
EDIT: oops, posted to the wrong person
Also, seems like that's a lot of dependencies for ggplot2. I'm wondering if this is really worth switching off of matplotlib. Sounds like all it's really doing is changing the method that you call ?
It is my second choice language these days after python, and the only one to use when you need a certain library.