I don't want to stray too far off topic, but I'm actually considering banning aarakocra from my PC race options.... They also like to portray their characters less like exotic winged creatures and more like humans with jet packs.
This mess is tough. I mean there you are, running your no-nonsense game of gritty fantasy. Your players are miserable peasants
and it’s amazing. They’ve got to choose between a hot meal and sleeping in an inn. Their horse is busted. Their weapons are scavenged pitchforks. Everyone is diseased,
covered in naughty word, and can only dream of that distant day when they’re able to afford pants. In short, they might die from an encounter with
a freaking cat, and everything is as it should be.
But then it happens. At long last, they’ve killed enough dire rats to hit third level. The wizard gets his invisibility spell, and now everything changes. The players can go wherever they want. They can sneak into the bandit king’s tent, the princess’s chambers, or the vaults of Ye Olde Banke. Soon their pockets are bulging with filthy lucre, and their swords are glowing with the blue light of a +1 enhancement bonus. A new way of playing the game has fallen at their feet.
Invisibility is, in my opinion, the first of three abilities that change the way the game is played. The third is of course teleportation points for guessing what the second one is.
Flight is one of those abilities that your players have to have. At some point in a fantasy game, they WILL encounter harpies or winged demons or
exceptionally mean canaries, and on that day they’re going to want a carpet/cape/cauldron/etc. of flying. After all, there’s nothing worse than straining your neck as you look skyward, watching as your buddies hog all the glory.
And so, because your players all can fly, you’re left sitting there as a GM with a pile of tear soaked campaign notes crumpled up on the table in front of you. All of a sudden you can’t put a mountain in their way, a pit trap, or a daring leap across a chasm. You can’t even give them ground-bound enemies sans projectile weapons. And as you're finding with this bird-man, scouting open-air locations becomes a real point. All of those game elements have gone away because the game space has acquired a third dimension. That’s what I mean when I say that flight changes the way the game is played. It’s a fundamental shift in adventure design and player capability. Aarakocra simply means that you have to deal with it a little earlier.