And what is your obsession with wi-fi? Few people spend $5000+ on a high-end SLR and glass with the intention of instant sharing. It is just not a feature that matters in these cameras. I bought a Nikon waterproof P&S to use on vacations, it has wi-fi built in, and I don't see why anyone would care.
Pretty sure the Nikon wireless dongles offer that functionality for people who want it. I don't think they're that popular though because people don't really care for wifi in their cameras.
Wifi may not be useful for you but I don't think it's a gimmick for everyone. Quite a few pros are starting to use live view on iPads. Especially in a controlled environment, it allows you to set stuff up and see how it'll show up in camera so you don't have to run back and forth. Wireless tethering is obviously a nice plus for location shoots where bringing a laptop is just a bit too much.
Also for event photographers, quite often they need to upload photos as the event unfolds. Processing your images and uploading them the next day is not good enough when people are shooting from phones... Wifi allows them to quickly access the file from a tablet/phone, do a quick edit, slap a caption and off it goes to web.
Products like CamRanger and Eyefi have been around for a while now and sell, if we could get those capabilities built into the cameras why not? Sadly, the current implementations are far from seamless but I'm sure it'll get there.