Remember, Activestate used to be Hip Communications. And MS gave Hip Communications a shedload of money to port and support perl on Win32, to make it easier for people to switch their applications from the Netscape web server to IIS.

I think this is probably the best business reason I have seen on this thread to explain MS using perl, rather than embrace / extending something similar. Netscape was a large threat to them, and being able to port existing apps from NS to IIS would have been a good selling point.