Thought - Grass

Why are we so obsessed with our grass?  What is so important about A) having a lawn of grass around our house and 2) keeping it well manicured?  Why did I just spend two hours mowing and trimming my yard?  And why does it feel so good when I look outside and see it?

It just doesn't make any sense.  Green is just a color.  Grass is just a plant.  But we like to see stretches of close-cropped lawn laid out before us.  There must be some hard-wiring inside humans, at least modern Americans, that makes us desire this aesthetic.  There are a couple reasons I can think of, perhaps none of which are true.

1. We want to feel one with nature.  In our increasingly urban lives, we see less and less nature.  Perhaps that's why we enjoy going to parks, watching on nature trails, going camping, and even looking at our yards.  Maybe the grass makes us feel that much closer to nature, which we miss when we're inside out houses and office buildings.
2. It's a status symbol.  Rich people can afford big yards.  They have trees, nice lawns, even ponds, lakes, ocean views.  And perhaps we desire that, we want to be like the wealthy people with the money to make even the outside of their houses look spotless.
3. No one likes to be judged.  I know I mow sometimes because I know it's getting high and I'm afraid someone will comment on my yard.  It's embarrassing when your grass is really high and people come over.  I don't know why, but it is, and perhaps we're all competing with each other to see who can mold the nicest backyard.

So, whatever the reason, when I stop to think about it I feel a little silly putting that much time and effort into keeping my grass looking nice.  I mean, so what if it was a yard of dirt, or blacktop, or sand?  If everyone started paving their backyards, would that start to feel normal?  Or would we desire trees and water and greenery and nature even more than we already do?