Unix is a good operating system for experienced users and programmers, because it was designed by such people. Everything a good programmer needs is present, but not much of anything else. A great example are the Unix "manpages" or manual pages. They are included with every system and completely cross-referenced, but you'll find extremely few tutorials or "getting started" guides. Experienced users find them very convenient, but the manpages can be overwhelming for a beginning Unix user.
During the last decennium, the user interface has improved tremenduously: a windowing system was added and grapghical user interfaces (GUIs) were being developed to easily administer a wide range of programs. Especially in the freely available Linux distibutions that emerged during the early 1990s as a response to the wide range of proprietary Unix systems, extreme effort has been put in developping a more userfriendly system.