Jakob Nielsen is always interesting to read, and a big part of the reason why is that he does his homework before he publishes an article.

I was just reading Write Articles, Not Blog Postings and it reflects a lot about what I believe has really worked for me on some of my web sites.

Jakob's summary of the article is:
To demonstrate world-class expertise, avoid quickly written, shallow postings. Instead, invest your time in thorough, value-added content that attracts paying customers.
My preferred summary is from much nearer the end of the article:
For most sites, the content is not the point. Instead, you want to answer customers' questions as rapidly as possible so that they'll advance in the sales cycle and start buying (or donate, or sign up for your newsletter, or whatever else you want them to do).

Elite, expertise-driven sites are the exception to the rule. For these sites, you don't care about 90% of users, because they want a lower level of quality than you provide and they'll never pay for your services. People looking for the quick hit and free advice are not your customers. Let them eat cake; let them read Wikipedia.
Another way of looking at that is: expert articles are the only ones that generate free quality natural authoritative inbound links over the long term.

Sure, you can win a lot of keywords with lower-quality pages once you build up your domain authority with expert articles -- but you have to build that authority first. And how is that authority built? With free quality natural inbound links from authoritative sites -- the links that only go to expert articles.