Drupal is a framework for building generated/dynamic webpages. People who take the time to learn it, find it saves them time and is very flexible. It also has a huge advantage in terms of documentation, even if most of it is pretty terrible.
Most of these people don't use community provided modules because the modules are too slow(as they are so generalized) and as you say, tend to not to be updated.
Well i happen to find Joomla to be extremely cluttered and non developer friendly. If you're a programmer i think Drupal is very good, i've done about 10 sites in it for customers so far. The best thing about it is integration with PHP code.