To add to subignition's point, there is a value in learning useful software. More complicated software means that there is a learning curve - so while you are less productive while learning how to use it, once you gain more experience, you ultimately become more productive. On the other hand, if you want the software to be useful to everyone regardless of his level of experience, you ultimately have to eliminate more complex functionality that makes the software more useful.

Software is increasingly being distilled down to more and more basic elements, and ultimately, I think that means that people are able to get less done with them these days. This is just my opinion, but in general I have seen computer literacy dropping and people's productivity likewise decreasing, at least from what I've observed from the 1990s up until today. Especially at work, the Linux users that I see are much more knowledgeable and productive than Apple users.

Or instead just not hiding things that need not be hidden, like file extensions, despite your OS relying on them for identifying types.

...No. I am saying that too much abstraction of how something actually works is detrimental to the end user. It's not about making things intentionally more complicated, it's about removing the need to understand key components of something ultimately causing more harm than good.