It is annoying.
But on the flip side, if the link was included, someone would have invariably commented that the "article reads like an ad". The authors can't win.
I disagree. I think it's MUCH worse when, for example, you read an article about a Kickstarter project on Mashable or TechCrunch only to find that clicking on the hyperlink leads to other articles on those sites about Kickstarter and not the actual project link. I think those sites have gotten better at linking directly when commenters complain.