Looks like they are taking their sweet time to fix it. However, you'll be pleased to know I found a work-around!
In Mavericks and Yosemite:
Open your home folder (/Users/yourusername) in the Finder. Depending on your Finder settings, this may be as easy as simply opening a new Finder window. Otherwise, choose Home from the Finder’s Go menu (Go > Home); or press Shift-Command-H.
Still in the Finder, choose View > Show View Options (or press Command-J).
Near the bottom of the resulting View-Options palette is a setting called Show Library Folder. Enable this option. Your Library folder is immediately visible.
Close the View-Options palette.
Your Library Folder is now visible in your 'Home'.
Now, go to the folder Library/Preferences/
Inside this folder, you need to DELETE this file:
unity.unknownworlds.Subnautica.plist
Reboot/Restart your Mac (or turn it off/on again). -VERY IMPORTANT-
Launch Steam and Subnautica, you should find your preferences are default again!
Be careful not to re-bind your mouse again, or you will need to do this all again!
--WARNING--
Now that the 'Library' folder is visible, remember to be very careful because, as mentioned above, deleting or moving the wrong file(s) inside this folder could cause an application to misbehave, to lose its settings, or even to lose data. You might want to follow the first steps again, in order to hide it again.
Comments
If you want you can reset them using these instructions:
jonas@unknownworlds.com try send an email to this address explaining the problem.