Truly, you nailed it on the head. Demographics. What they need to sell advertising to make money to have an income and pay for the sites expenses. Maybe they want more? From what I see, the Beta says this site will become less. Hopefully I am wrong, but my experience over the years in all products has been the more a company tries to look like another company, the more they are abandoning their current market in favor of a different market. Most people still think the grass is greener in the other yard. If the site heads that way, I will not follow. I will just aggregate my own news and look elsewhere for online social discussions.
Of course, the reality is, as slashdot leaves its old product behind, the market it once served will seek out and likely find or create a replacement. Markets and people tend to do those things and their are many brilliant people in this crowd with enough gumption to do just that.