But DM that very statement is actually wrong. I learned Dolphin and returned to help, HL Learned and returned, Caltrade learned and returned, Dosdawg, Magnasoft, Yourself DM and many many others. GuyPC, Dolphinmods until he was chased away, Killerhaii and the list just goes on and on. The difference between D and other community softwares:

Wordpress: mainly for blogging, you do have to pay if you want the multi-blogger version.
PHPBB: Mainly for Forums with a weak IM and E-mail system integrated see more into it. Awesome Moderation controls
Joomla: Social Networking software severely lacking in comparison to D. Nowhere near the options that D has.
Drupal: I don't know much about that one admittedly.

But my point is, most of these are for small nice type things that are not meant to have a huge amount of functionality. What the OP is missing is the amount time it takes anyone to learn D. Crap I spent almost a year on it myself becoming comfortable and able to understand it all. The others can give clear cut instructions because they are very basic in comparison to D, hell, most of the others will run on almost any server set up. D is truly a unique product and as such it takes courage to run it.