The vertical grille in front of the radiator is there to protect the radiator vanes from things being hurled in it's direction.
The grille is angled toward the air scoop (often called by riders the radiator shroud).
This way, you get frontal protection as well as airflow via the angled grille.
This technique has been used on liquid-cooled motocross, enduro, off-road, and dual-purpose bikes since practically day one.
The one I DID remove from both my WR-250R and WR-250X is the silly black plastic duct BEHIND the radiator.
This is supposed to deflect hot air from the radiator away from the rider's leg, but since I always rode in motocross boots (WR-250R) or a leather roadrace suit and boots (WR-250X), I didn't feel any hot air bothering me.