All of these hardware questions must be analyzed in the lens of the times. The global economic situation is still fragile. The choice often is not simply which is better or cheaper, but which is more reputable. A new Windows OS is an unknown quantity. A Windows tablet is an unknown quantity since it hasn't been done until recently. So, it makes sense that the pickup for anything that is new is going to be a little slow. Apple has more or less been seen as first to the tablet market, so much of the time it is the default response from consumers who aren't up for taking a risk. It's why Google's Android, despite its popularity, has taken so long to make serious traction against Apple's and its iOS. It's why Window's tablets have taken until now to show real growth numbers.
This applies not just to computers, but many industries. We are in a difficult financial situation globally. People don't have a lot of money to spend at will, and even those that do have certain psychological incentives not to (concern about if they'll be able to keep their jobs, if another crisis is around the corner). As such, the cycles on products have to lengthen. We have to do a better job at recognizing that. Potential successes are going to take a little more time to reveal themselves.