No offense, but the article comes across too "Dave Ramsey'ish" for me. The basic message is well intentioned, and generally applies well to a good portion of people, but ignores the greater reality which provides sound financial reasons for debt. Despite the addendum of "Jason, I should have said net debt, as in more debt than investments" in the comments, the concept of "productive debt" vs "harmful debt" really isn't clarified.
More importantly, however, I'd say that while the article implies "debt" is causing the "slavery", the truth (somewhat hinted at if you read between the lines but not clearly stated) is that financial independence is required to be "free" of worry for those obligations. Of course, when you try to boil down complex topics like all of personal finance into a 1 page article, stuff is going to be missed.