Same reason they used to teach in Pascal. Python illustrates programming concepts very well.
It will be interesting to see if C# can make the transition from being a "Microsoft language" to being an accepted standard on other platforms. I think it's kind of silly to still have so much language fragmentation so late in the computing revolution, but no doubt we will continue to see new ones invented every year. :)
When was there a revolution? Another stupid buzz phrase that needs to die.