Donald Norman wrote a relevant column in ACM Interactions, Vol.12, No 4 (2005), pp. 14-19: Fresh: Human-centered design considered harmful. His point is that user-centered design is now treated as accepted wisdom, which is bad since:

One concern is that the focus upon individual people (or groups) might improve things for them at the cost of making it worse for others. The more something is tailored for the particular likes, dislikes, skills, and needs of a particular target population, the less likely it will be appropriate for others.

The individual is a moving target. Design for the individual of today, and the design will be wrong tomorrow. Indeed, the more successful the product, the more that it will no longer be appropriate. This is because as individuals gain proficiency in usage, they need different interfaces than were required when they were beginners. In addition, the successful product often leads to unanticipated new uses that are very apt not to be well supported by the original design.

But there are more-serious concerns: First, the focus upon humans detracts from support for the activities themselves; second, too much attention to the needs of the users can lead to a lack of cohesion and added complexity in the design. Consider the dynamic nature of applications, where any task requires a sequence of operations, and activities can comprise multiple, overlapping tasks. Here is where the difference in focus becomes evident, and where the weakness of the focus on the users shows up. (...) Yes, listening to customers is always wise, but acceding to their requests can lead to overly complex designs. Several major software companies, proud of their human-centered philosophy, suffer from this problem.

Donald then explains what he means:

Maybe what is needed is more activity-centered design; Maybe failures come from a shallow understanding of the needs of the activities that are to be supported.(...) The focus upon the human may be misguided. A focus on the activities rather than the people might bring benefits. Moreover, substituting activity-centered for human-centered design does not mean discarding all that we have learned. Activities involve people, and so any system that supports the activities must of necessity support the people who perform them.

Why do I blog this? just another a brick about the lively debate between human-centered design and activity-centered design.