[rpier001]

> It seems likely that R could have been designed to have the same strengths without having so many weird and arbitrary quirks.

Not really... at least not practically. R is a successor to S which was written in 1976 (fun talk on the history: http://blog.revolutionanalytics.com/2016/07/rick-becker-s-ta...).

Many of the arbitrary quirks started out for the sake of backward compatibility with S. All that being said, yeah, you could probably design a 'modern R' without the weird and arbitrary quirks.