Via EdTechPost comes this well-written criticism of open source software applications. Michelle Levesque cites the major problems as being:
Poor user interface design
Lack of documentation
Feature-creep
Made by programmers for programmers (not focused on a target audience)
Blindness to other non-OS developed functions & features
This shows once again that there is a potential business model in adding value (by addressing these five problem areas) and selling open source related services & add-ons. The JBoss.com model seems to be a good example of this.