One of the main issues with analog meter is that the control torque in the instrument is provided by spring. A meter stops deflection when deflecting torque is same as controling torque and thus when there is an issue with spring the measured quantity can be incorrect.
However, analog meter have one huge advantage: by noticing how rapidly the pointer deflects you can sense the magnitude of force changing it; here faster deflection would imply faster acceleration, and suppose you were throttling to accelerate to a certain speed and you notice the rate of deflection increasing rather rapidly that would imply you are putting in more force than required and thus may reduce throttling in order to avoid overspeeding. Similarly if you...
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are generating very low amount of force your pointer will move very slowly.
The arrangement with LED avoids the problem with spring, while simultaneously allowing one to sense acceleration by seeing how fast the LED's get lit up

Pretty nifty design actually :)