No,
and here's why:
Pubic Hair is a barrier, yes, keeping nast away from holes, but really, how much hair is there around your mouth? Couple this with the fact that, on the male anatomy there is an ample amount of hair and none of it is adjacent to said orifice. Consider, in addition, the front lawn that really couldn't be there to screen out much of anything.
No, pubic hair serves a different function.
If you are a male, or are French, lift up your arm and inspect the point where it joins the torso. You will note a presence of hair and a corrosponding lack of any sort of orifice. Curious, isn't it?
The hair is there to reduce friction between these meeting planes of skin.
"But", you say, "What about the pubic hair? There's no other appendage of your body that rubs against that on a regular basis and would need hairy lubrication! Your theory is flawed!"
To this I reply "You're right. I'm not worried about my skin rubbing against that area, I'm worried about someone else's."
Yes, that's right, its there to prevent chafing and friction -- damage to that oh-so-sensitive skin -- in the most evolutionarily advantageous of acts itself. Not only this, it can actually serve to stimulate the skin somewhat -- tiny hairs running across sensitive nerves...
So, unless we develop sexless reproduction, we will remain with a lawn.