Re: I have doubts
In fact, I did read the article. If you could reread my comment, please, you will perhaps notice that I mention video as a reason why data limits on WiFi wouldn't apply to devices such as this, as they will not be sending a lot of data.
Hospitals and factories are very often highly networked. They are indoors, and there is electricity running everywhere. Machines, lighting, communications infrastructure, all are there. Especially with hospitals, there are also computers everywhere requiring network activity, not to mention patients who may have phones and laptops with them. Installing WiFi access points in an environment like this would make a lot of sense. FYI, a single WiFi access point doesn't cost anything like $200. A network covering a factory wouldn't be cheap, true, but depending on use case, it could be worthwhile. However, in a highly electrified location, many of the sensors could be directly wired.
The use cases that make the most sense to me are those that need a long range where electricity and networking aren't available, most of which are outdoors. I can think of some use cases indoors as well. If you had a factory without WiFi and you only had one or two sensors, then installing WiFi only for those might have little point. However, if that were the case, I'd assume you could do that more efficiently by having those sensors attached to whatever they're sensing, as there are not that many of them.