Sharepoint vs Drupal

Depending on which license you purchase, Sharepoint can cost from US$ 4000 - 25,000. But what does that price get you? It doesn't offer any advantages over free and open source software (e.g. Drupal) - atleast according to this tweet.

Hardly a fair sample, but too tempting not to highlight, here's a chance tweet in the twitterverse (I don't know the author, just happened upon it at http://search.twitter.com):