This is all that IoT needs, though. It's not about streaming video or music or something, it's about a sensor that goes high when somebody is sitting in a chair, or that sends an integer value once every few minutes.
I think you answered your own question -- of course WiFi makes sense for small/short range networks. Its cheap and fast.
These technologies are more exciting because you are talking about realistic coverage areas of square kilometers with inexpensive, unlicensed radios. Think of something like a large natural gas pumping field -- there are tons of industrial sensors and controls spread out over a fairly large area that don't need to send much data. I work in the radio industry, and these technologies, if they live up to their hype, will be industry disrupting.
