Since you decreased the front droop, you also decreased the amount by which the front rises on acceleration. This results in lesser weight transferred FROM the front towards the rear (during acceleration). This means, you're keeping more weight on the front tires and you should have more traction as a result.
Decreasing the droop on the rear also prevents weight from transferring from the rear towards the front on deceleration. This translates to more traction on the rear so your tail don't go whipping around during cornering.