I hear what you are saying.....
but... to use a Pi, you need to be a techy.. or at least a computer enthusiast at least.... unless you are doing stuff which is completely configured already....
As it seems your primary goal is to be totally wireless with the Horizon, then I think you're going to struggle with ANY solution due to the physics of wireless... it just doesn't have the same throughput as USB3. But the biggest problem is, you need *something* to transmit the data from the camera to your main computer (the Cameras are not "servers").... that's where the Pi solution came in..
Also, not sure what you mean about Atik rewriting Atik Air? Air is already a 2-tier setup; one piece runs on the Windows (the client, which talks to whatever you use to run the camera - Artemis capture, Sharpcap, etc) & the other runs as a "server" (on the Pi where the camera is physically connected). What would they re-write? The Pi is acting as a forwarding platform for the camera.... you would still need some sort of computer at the camera end in order to transmit the data.
For a lot of people, the wireless solution is fine as so long as you don't need to stream large amounts of data real-time.. that means *most* astro cameras are catered for.
Sorry... but I have not heard of anyone with a reasonably cheap & easy method of transmitting large amounts of data from a camera to a computer.... AFAIK, any USB->Wifi adapter needs a computer... can't plug directly into a camera...
Phil