[sunnybunny]

It would be a mistake to assume that readers are all the news sites optimize for. Don't forget that they get readers to get impressions, and impressions to get ad dollars.

By increasing the real estate focused on creating more clicks, they increase the chances they can get somebody's attention, send them to a new page, and thus create another impression, and more money generated.

It's the same reason that news sites will have a "Top 10" article with images and divide the content up into essentially 10 sections you have to keep hitting Next to see more on. More page loads = more impressions = more $$. Simple

Additionally, pages rank higher for SEO in SERPS when they have social proof that the content is engaging. So yes, the social sharing is necessary.

So while I agree your comments on how to optimize purely for readers are valid, you may be forgetting to take other things into account.