It's actually worse than this if you look at the config files. I suspect that there is next to no reason to use the throttle instead of keyboard controls for controlling the collective.

Wish this could change but I think its baked into Arma3. Maybe Arma4.

You can use DXtweak2 to solve this issue. Here is the solution: http://forums.bistudio.com/showthread.php?121773-A-fix-for-Full-Axis-throttle-mapping-Possible-Solution-inside!

Hope BIS will fix this.

Well that changes your joystick map entirely not just for a selected application. This means it will change all of my other maps for other games, so its not a viable option.

Please also check the comment here - http://feedback.arma3.com/view.php?id=6888#c74964 - for solution.

Thanks for the feedback!