I use Python instead of R unless I'm told to use R. I hate using R, even if there are better libraries written for it than the Python equivalents. I can't stand the terrible naming conventions (seriously, can't you at least be consistent with CORE FUNCTION names?) and ridiculous amount of data structures. There are vectors, lists, matrices, tables, data frames, S4 classes, environments, oh my... I've been programming in R for a couple of years now and it still takes me around 2-3 tries to figure out what's stored in a variable and how to access it. Do I need two ['s, a trailing comma inside the [], etc.
Debugging R basically seems to mean "use a hack to generate stack traces."
Maybe I'm just stupid, but I see _absolutely_ no reason to encourage use of R over Python. I love lisp and the ideas it espouses, but R seems to take the worst from that world.