Restrictions only matter when they limit you from doing things you want to do. For the vast majority of consumers, the closed nature of the iPad isn't a restriction, it's a convenience.
We need to understand that the average HN reader is not the target market here. We're generally more technical and are willing to tolerate more complexity and maintenance in return for a greater level of freedom over our software and devices. The things we regard as important are not seen the same way by most people. They just want an appliance that makes the things they do every day as easy and hassle-free as possible.