Dear SEO spammers and Googlemancers: go away. We actively don’t care about your page rank.
(That TechCrunch article is really special: make several errors of fact, assume they come from malice and start a conspiracy theory.)
Our responsibility as a top 10 site is to our readers. Our responsibility is not to a third party (search engine optimisers) to make them look good to a fourth party (Google). People whose interest in Wikipedia is page rank are in no way, shape or form our constituency. Because their interest is, fundamentally, spamming.
Pagerank is not a consideration for Wikipedia — it contributes nothing to the project of writing an encyclopedia. This is why SEOs and Googlemancers find it so hard to find anyone at Wikipedia or Wikimedia who cares.
The interwiki map is for the convenience of the projects. Not for the SEO spammers.