Think about it, it'd take much, much longer to get to get anywhere, most importantly right after beginning of the game, for example, at 40 knots (fast DD speed), it'd take 8 minutes to cover 10km. Which doesn't even put you in range to do anything, so make that 16 minutes before you can do *anything*.
The game is already relatively slow paced for an online shooter.
I do admit i was a bit put off when i first realized this, but it really wouldn't work otherwise, i'm just annoyed that they won't say just say outright what's going on and give relevant stat.