Maybe you're not playing the same game I am.
I generally make it a point to stock up on certain weapons as a warhawk, which can considerably balance your ability to take out a foot soldier.
Snagging up a TOW missile, and maybe the ground bombs will make it amazingly easy to kill a foot soldier.
If you try to take him on with only your machine gun and swarm missiles, it'll be a tad harder.
Also, RPG missiles are very VERY easy to dodge if you're in flight, but harder when you're hovering (actually, Impossible when hovering).
It's balance at it's best. Making Warhawks overpowered may 'seem' cool, but it will ultimately kill the game. If you see a foot soldier, land, get out, and kill his ass. Then get back in your warhawk and continue. Works every time.