When each shipment nets maybe $30,000,000 for the shipping company and you pay about £20,000 for the crew during that time, you'd need to save a lot of money elsewhere to make this worthwhile.
You're forgetting costs associated with crew beyond pay. You also have to pay for food, insurance etc.. there's the risk of hostages being taken. Additionally, removing the bridge/crew quarters makes for more space to put containers, the ships could end up looking like barges with the entire top surface covered in containers.
I'm not sure that's accurate. The article mentions this:
>Crew costs of $3,299 a day account for about 44 percent of total operating expenses for a large container ship, according to Moore Stephens LLP, an industry accountant and consultant.
That would be what, 10 days at sea? Are they really that fast? Even if so, where does 44% come from?