Open-source applications often are criticized for their lack of a friendly user interface. This is largely because open-source programmers are writing the software for themselves and their colleagues, which means that anything other than core functionality is cast aside.
The authors of WordPress, to their credit, have spent a great deal of time on the user interface, trying to ensure that it is straightforward and unsurprising for nontechnical users.
Agreed. WordPress has a beautiful user interface for an open source project.