"3. The Critical Engineer deconstructs and incites suspicion of rich user experiences."

I think what this tenet is talking about them importance of not simply accepting what is offered out there in the world. Instead, we need to always keep a critical eye on the new technologies and as well as the new experiences that they claim to bring. We need to understand why they are developed and how they are adapted before we take any actions. In addition, it is in fact almost always the case that a rich user experience mutually benefits not only the users themselves but also the company who provides the service/product. With the spreading of information technology today, information is traveling at a rate that is no longer limited by space and time. Thus this also enhances the effectiveness of "word of mouth". By providing good experience with existing users, this means they business has a better chance of reaching a larger group of potential users though the self-identified promotors.