You would think that Business Week would know better than to perpetuate the Lump of Labor fallacy.
On reflection, there is a difference between the Lump of Labor fallacy and a particular job opening up. If your only way to advance (say within a company) is to wait for someone above you to advance/leave/retire, then you personally will be affected by later retirement ages. It's not always easy to see alternatives to waiting, and they might come with risks you'd rather not accept.
In one company for a particular position yes, the article seemed to be insinuating some sort of general notion that jobs are a finite resource. It especially comes across because of the finger pointing at an entire generation.
Exactly. If the the powers that control the shape of policy in this country (mostly wealthy & large corporations that have politicos in their pocket) cared about creating jobs as opposed to pilfering from the poor and middle class, we wouldn't be in this situation.