It's that it is just another "gamey" addition. Lets have a HUD with all the information needed, alt, speed, climb angle, and any other thing you can think of. Why, because people are too lazy to learn, and practice "looking down" to see their gauges.
Lets dumb down the game so its like an arcade game that you pay a quarter a flight! The more arcade like the game gets the worst the game over all will be.
Basically what I'm saying is LEARN THE GAME! PRACTICE! instead of asking HTC to make short cuts so you don't have to bother.