I agree with the basic premise, that people generally don't communicate clearly enough for immediate action to be taken based on their utterances. Humans are brilliant at understanding other humans, and we get it wrong. I think he's right to sneer at natural language interfaces for certain kinds of tasks, but I think there are two important points he fails to make. One is that there are other tasks for which it may not be a catastrophic failure, and that computers could conceivably someday understand our speech better than people do. I haven't seen the hype he's referring to, so I don't know whether people are hyping natural speech or just spoken words.
Unnatural speech can have great applications though, even with current technology.
It sure would be nice if the air conditioner were on. What I like about unnatural language is that it's not only clear, it's explicit. Not only is it clear to the machine when it's being addressed, it's clear to me when I'm addressing it. The down side is that we have to learn the command set. With better programming, a system could be more flexible, but there will always be limitations, unless it really understands everything we say, which is incredibly hard.