I used to work a lot with R many years ago. I was shocked to find how bad the documentation was, and worse how rude and unfriendly the "community" of grumpy professors was. I shudder to think of the horrible meanness towards beginners asking questions on the mailing list.
I got so fed up I even wrote a book about R data visualisation. But this was all just around the time ggplot2 came out. Unfortunately I stopped using R soon after, but since then Hadley has single-handedly done more good for the language than anyone else.
I don't know what the R community is like now, and whether people like Hadley have made it friendlier, but it's clearly one reason Python is superior.