It's not (just) the hardware, it's the software implementation. Certainly such a thing could have existed previously, but no one appears to have made it work as

It's not (just) the hardware, it's the software implementation. Certainly such a thing could have existed previously, but no one appears to have made it work as well as it does on iPhone just now, although that will likely change. Marketing terms are used constantly for referring to specific flavours of technology. For example, Google Now, Cortana and Siri. Language and people are flexible enough to cope with multiple terms for a technology. Also, it's faster to type than "microphone which samples and uploads to an external voice processing server which returns system commands".