“The intuitiveness of a system is the inverse of the distance between the user’s “current knowledge” (what they already know how to do) and the “target knowledge” needed to use that system.
There are two ways to narrow that distance: You can increase the user’s current knowledge via training (never a good approach on the public web – no one ever reads instructions on how to use a website), or you can decrease the target knowledge required to use the system.
So, simplifying systems is a good thing, right? Well, maybe. Simplification changes the nature of the “target knowledge” needed to use a system, but doesn’t linearly move it closer to the user’s knowledge. Simplification invariably introduces change, and change invariably requires adaptation by people familiar with the system being simplified. A system can be redesigned to be more usable (and intuitive) to brand new users, but with a website, that is never the full picture.”
Leia o artigo completo: The Disaster of Redesign (inglês)