I work at a Microsoft Office Universe (They refuse to know of any tools besides Word and you are a tech god if you use Excel) So when I finish my reports in R I actually give them Office Documents. The presentation is actually Power Point and the documents are in Word.
I left Python and Pandas and the visualization was far behind what R had in its tool chain. I still feel that R does visualizations best.
RStudio (A true IDE) was better for my work flow than IPython/Juypter. I actually really missed IPython at first and than slowly I grew to love RStudio.
Not a wall, maybe a paper cut. A 1 index (R) over a 0 index (Python) is pretty smart for doing statistics, less errors.
I also liked the flexibility to use whatever I wanted to do my work. Was difficult at first than learned to love the fact that there were 3 good ways to do something.
Functional Programming. You can do some good functional programming with R. Functions are first class citizens.
Biggest reason for anyone to switch is Hadley Wickham and his work with RStudio. It really is amazing everything that he has done for R in the last 5 years.
Once again Python will get the job done but these are some of the reasons why I switched.