Enh, the tech space is very much innovate or die. So yeah, they could probably throw everything in maintenance mode and make a reduced headcount work, but if AWS goes stagnant it’s entirely likely that Amazon goes the way of IBM and Motorol. Especially when someone (likely, Microsoft or Google) comes to take a slice of the AWS market share.
Same reason most things are funny, or at least mildly amusing: inversion of expectations.