Earlier quoted context omitted.
Services like operating the walkway and the tugs that push-back the plane from the gate are often outsourced. Perhaps that's the connection... in most of the cases where the people did a terrible job, it's because the role's been outsourced.
I think the article nails this on the head, management doesn't care about it's employees, and the employees pass this on to the customer. They care so little that they don't even want core pieces of their business done by their own people. It reminds me of a cable co in canada called Rogers, the entire thing is a bunch of outsourced services glued together with a couple sales people.
Ultimately I think it comes down to cost. As airlines predominantly compete on ticket price, they'll do whatever it takes to reduce that (outsource their logistics, operations, flight planning, etc.) Hell, Ryanair in Europe make their pilots pay for their uniform. All about getting the fare as low as possible, consequences be damned.