Maybe he meant "die" in the sense that the project will die without the rover's ability.

Personally, I think we should send machines capable of building infrastructure as soon as possible, if we ever want to colonize, and self-replicating machines would be an elegant way to accomplish that.

Your philosophical/linguistic question is a fun one, though. The classic cogsci example of this is that a thermostat can be most easily described in terms of intent. Often, the people using a machine have sound cognitive reasons for anthropomorphizing: a lot of our brain power is wired toward socialization, so why not use those patterns to interface with your equipment?

It's tough to say whether our perception of intentionality is just convenient pattern-matching, or if our whole concept of intent is just a pragmatic device we have developed to deal with responsive systems. But as an engineer, I certainly think of almost anything I've made as "alive" whenever it's in working order.