He was saying in his post that considering proper usability to a designer is analogous to people putting on pants. There are plenty of people who are designers who might not have learned that in or out of school. Getting the details right on which buttons should take you to what screen and what they should say is not always part of an interaction designer’s experience or schooling.

Which is why the people hired to do that stuff usually have the knowledge, whether or not they are designers. My main point is that just because someone is a designer or even interaction designer doesn’t mean they always have the best usability sense or even include it in their process.

My answer is yes, interaction designers, as part of their value, consider and design for behavior. In essence, we make things more usable as part of our process. Sure, someone can specialize in that. But usability isn’t the thing that makes great design.

Jakob has been riding his on curtails for years, and has long past his usefulness; or perhaps, one might say, he is a usability disaster.