Lawns are good for...what, exactly?

The best use of lawn grass that I can imagine is as fodder for grazing animals. What does that grass do for us really? Who came up with the notion that a well manicured and cared for patch of mixed grasses is attractive?  http://www.american-lawns.com/history/history_lawn.html

I would ever so much rather have a 'yard' full of dandelions, herbs and vegetables!