I use flight paths when the flight time to the content is counted in minutes.
I will not pilot my character and watch the screen for minutes, and I’ve had times when I tried to just auto-run, only to misjudge when to return (or got distracted) and auto-run off the map and die to fatigue.
And for Blizzard, the more I find myself needing to take long flights, the more I find myself saying why bother, which ultimately leads to me dropping my sub.
Stop padding in time, and you might get more money from me - but keep padding it in for god knows why and expect to get less.