Contra-question: Have you bound the throttle axis to absolute throttle axis in controls screen?
...Anyway, you don't need the throttle control as much as you might think. I use almost exclusively the Full throttle - zero throttle keys, and sometimes match speed.
I also have them set up similarly to X-Wing vs TIE Fighter key layout, as in
Backspace = 100 % Throttle
* = 0 % throttle (or whatever is the key in your layout, next to enter, in third row [number row bing the first] )
Enter = match throttle
Keys give faster control in this case.
Exept if you use glide build and fly glide-enabled ship...
