> those packages tend to be more extensively peer-reviewed This is the key as far as I can see. I am fortunate enough to work closely with some big names in st

> those packages tend to be more extensively peer-reviewed This is the key as far as I can see. I am fortunate enough to work closely with some big names in statistics. They do everything in R, there's not a thought of using another language. All the leading research in statistical methods gets published in R, thus the "reference" implementations become those R packages. Even if you find an equivalent implementation somewhere else, you can't say it's been through the rigour of peer review that the R version has.