Functional Mainstream

From reading, "Functional Programming Doesn't Work (and what to do about it)" - I found this post along similar lines, "Functional Programming Went Mainstream Years Ago":

You can view a Perl (or Python or Ruby or Lua or Rebol) program as a series of small functional programs connected by a lightweight imperative program...0% of the impressive magic from early functional languages has been rolled into mainstream languages. That last 10%, well, it's not clear that anyone is really wanting it or that the benefits are actually there. Purity has some advantages, but it's so convenient and useful to directly modify a dictionary in Python. Fold and map are beautiful, but they work just as well in the guise of a foreach loop.