What you'll discover is that they face plenty of complicated problems in their own work and they don't want to devote brain cells to your website or its design. They want to get in, get out, and move on with their own tasks. Design complexity is a barrier for users. The Web is about freedom of movement. Anything that stands in the way of immediate task completion will negatively impact the user's experience.
Some people are smarter than others.
From such a vantage point, it is easy to think of other people as being stupid. Not that they are stupid. Nonetheless, it might be true that some people do not have enough intelligence to use sophisticated and advanced high-tech systems. Not likely at this point. Even in the most wired societies like the United States and Scandinavia, only half the population is currently using the Internet.