The "camera adapter" is only necessary because the iPad doesn't have a USB port. The only way to get a USB device connected is with an adapter, and originally, the only (type of) connectable device Apple supported was a camera, hence the name of the adapter.
Now, despite the officially unsupported status of mech boards, they still worked when connected, albeit with a highly irritating popup box announcing the detection of an unsupported device every time the iPad was awakened.
Luckily, though, Apple recently (and by recently I mean last year) eliminated the popup box, and we can now use mech boards and they feel more like first-class citizens even though the adapter is still necessary. I was really hoping that the introduction of the smart connector on the iPad Pro line of tablets would lead to the release of "smart dock" devices that would provide a USB port for proper support of mech keyboards. Doesn't seem like any vendors have jumped on that opportunity, unfortunately.
