Usability practitioners face some resistance on an ongoing basis—it is the nature of the development process. The usability community needs to maintain enough respect so that it can get the users' needs fulfilled without being marginalized, ignored, or overrun with technology taking precedence over usability.
For example, a usability designer may tell a developer that users need a display that collects all their data in one place. The developer quickly sees that this is hard to support: It will be necessary to link calls to a number of databases, and greater processing power will be needed. The developer naturally wonders whether this usability practitioner knows what is going on. Is this really going to make a difference to the user? Will it make a difference to the business?