To be fair, many of these people are actually disabled. It's just that previously they could work. Like the article says, their managers cared about them and and had the capacity to let them take lower-impact positions that they were capable of doing.
We don't appreciate how difficult it can be to employ these marginally capable workers. Keeping these people on staff at a small company raises health and operational insurance costs pretty dramatically, so it can be hard to justify keeping them on staff, even if you wanted to.
Disability is also pretty difficult to get, despite how the news makes it out to be easy. My father had multiple heart attacks and cancer, and he's still fighting to get on disability. And when he does, it will take years to come into full-effect.