This article seems like an excuse to criticize IE. "Instapaper is severely degraded in this browser" is fine. "... because IE does not support basic web standards" comes off as catty. I understand the frustration that IE isn't fully compatible, but as engineers it's not our job to change the world to suit our own needs; we shouldn't be converting users to a different architecture or web browser. IMO, 10% is a lot of…
Often rubbing something in someone's face is the only way to evoke change. To degrade the experience and let the user know why it's been degraded gives them a clearer understanding of the problem. Being struck with the same problem enough times tends to get someone to act to solve it.