Why is building components in Drupal so difficult?

Lots of work in the community is happening around how to best design, define, theme, and author components in Drupal, and seemingly everyone has their open source/contrib solution to make at least one aspect of building a component system easier. The question is why? What problems are all of these solutions looking to overcome? Why is the community not consolidating on a common approach?

In this session, we'll establish the parts of an individual component and what a component system needs to be successful. From there we'll look at various component system architectures and try to identify common pain points we all experience. To wrap we'll see what discussions are happening in core's issue queue and if there are bigger problems we should be addressing as a community.