I’m not that surprised, because the article is focused on how to be productive for longer, whereas—at least for me—the value of Beeminder is in making sure I make consistent progress towards my goals. In fact, the more productive and focused on my primary tasks I am, the more likely it is that my secondary tasks will get neglected (hence my primary use case for Beeminder).
P.S. This article and the HN comments literally just made me realize I’m a workaholic and so is everyone I’m surrounded by, because 200 (~6.7 hours/day if you work on weekends, which I do) actually seems on the low side to me. Though it’s not really an apples-to-apples comparison, because my friends and I are young and don’t have children to take care of, and a good amount of our work is only moderately-demanding like reading, instead of writing or coding.