They have two primary sources for content:

1) In-house writers, and

2) Feeds.

The in-house writers are the web staff you mentioned, and if you see content with interactive features, either the content, the interactive feature, or both originated with an in-house writer.

In many (most?) cases, the feeds come in from either the news services, or from business partners or corporate cousins, and typically by way of an automated process. At CNN, we also had an automated process to remove Associated Press and Reuters content, since their license for online use only allowed 2 or 3 weeks (I forget which) of availability.

Typically, the feed content comes in as it was provided to other sources (usually newspapers), and most news sites don’t bother to spruce it up unless it’s being published as part of a package with other in-house content. This is partly because that content is more transient — it will only live on the site for 2 or 3 weeks, and it’s more frequently updated as events require.

In the post-dotcom crash era, in-house employees have been laid off, and more and more of the content is provided without human intervention, hence no hyperlinks.

At CNN specifically, they’re trying to get broadcast news staff to produce more web content, rather than paying dedicated web staff, but writers who see the web site as an extra duty piled on an already heavy load are unlikely to go the extra mile to massage their stories for the web.