It seems to me that these sorts of devices are using WiFi for jobs that are better suited to Bluetooth LE. Most wireless applications I'd have in mind wouldn't need a server at all, since they'd be intended for use within the same room or the same house. But WiFi requires me to drag in an entire HTTP server infrastructure whether I want one or not, because my PC can only talk to one access point at a time. It also requires a lot of heavyweight configuration work just to add the device to my secured WiFi network.