IBM and KM

I came accross an article titled IBM's KM Strategy, at KMWorld. It discuss the very first beginnings of Knowledge Management inside IBM. How it has actually been really strong with the explicit knowledge exchange, i.e. asset management, through the existence of different Intellectual Capital repositories, beingKnowledgeView (From Global Business Services) one of the most powerful and popular ones, and other key areas of how KM has been envisioned all along. Such as:

Asset Management: An asset at IBM doesn't necessarily have the same definition that an Accountant would have. Every employee's knowledge is an asset to the organization. By leveraging their knowledge, the company may grow and become stronger and more competitive. Through asset management IBM allows for a worldwide Asset Reuse program for Global Technology Services where knowledge workers can capture key assets and then make them able for reuse at a later time. 

 Expertise Location: BluePages -the universal employee directory that feeds everything else like Fringe Contacts. 

Collaboration: Using different tools such as Collaboration Central, Teamrooms, Jams, ThinkPlace (Sharing and collaborating on ideas across the timezones, geographies and business units), etc.

On-demand Learning: Learning@IBM is a new way to help promote learning throughout the organisation where the employees have full control of their own learning process - methods, types, etc.

One thing I would like to not - I noticed that IBM's KM tools have all been very much focused primarily on transferring explicit knowledge as opposed to a more balanced approach between the sharing of explicit and tacit knowledge. Why is that?