Re: Thrashing about wildly looking for straws to clutch...
Where did I say energy consumption didn't matter ?
In the examples you mention I'd hope that the programmers were aware of the power consumption issue and used the most appropriate languages and techniques to minimise that.
The reason we're using so much energy is because we have a "throw more CPU's at it" mentality rather than 'can we write it better'.
Rust (and any other language) isn't going to solve the problem - (almost) nobody tries to write efficient code anymore or revisits their old code to clean it up - if it works - leave it.
All languages allow you to produce bad, inefficient results, e.g. pretty much everybody would write a bubble sort, rust is no exception so using power consumption as a marketing message is spurious.