Why is the tree one of the hardest things to get right in 3d games?

[A Black Falcon]

I just find those "crossed polygon" trees awful looking... make it a crude 3d tree, but make it 3d... the only worse kind of tree is the "treewall" -- you know, that flat texture on the edge of the track (saying that because it's usually done that way in racing games) that shows an image of a forest... so bad...

Oh, and yes, grass is another issue. Newer games do do it better, though, with some taller grasses in addition to the normal "the world has been mowed" stuff...