Kathy Sierra asks if tools make us dumber. She provides some apt examples, where users end up relying so much on the machine that they get dumb. I would call them slaves rather than users.
I have maintained that the key benefit of tools, especially software tools, is automation. Automation can boost performance, productivity and efficiency. It cannot replace your knowledge or the need for knowledge. The need for knowledge can only be judged by its importance in your task. Whether writers who publish on the Web need to know HTML or not depends on importance of HTML for them. If WYSIWYG editors are not there, they might simply write in text files and put it on the Web. A calculator can relieve you of the atomic mathematical operations and let you focus on providing a better customer service. Unfortunately, mathematics plays a much important role in businesses, so relying only on the calculator might not be enough. There have to be ways of calculating the price even without it, whether it is because it is not available or because it is erroneous.
As a software developer, I use IDEs to write code. However, coding plays an important role for me, so I make myself comfortable even in plain text editors like vim. Worst case, I am also ready to write code on a piece of paper if the computer itself is not temporarily available. I want to be a user, not a slave of the tools I use. I am clear that tools play a critical role in my everyday life, but I keep enough distance with them to keep myself alive without them or even to migrate to a better one in future. I can complain all I want if I do not get the tools of my choice, but that cannot be a reason to not do the business, in my case, deliver to a client.
I do not think tools make us dumber. I think they make us lazy at times, which we can very quickly use to make ourselves dumber. Our need for knowledge is dependent on its importance in our task. Only our productivity can depend on the tool, not the knowledge. The tool does not want to become our master, we want to become its slaves.