I agree that onion grass/weed is a weed Greg. I find it isn't very convenient to remove it from a grass area by spraying it though, since it is moderately resistant to glyphosate and you end up with a whole lot of 1.5 inch circles of dead grass all over the place. I also agree that, at least in my experience, you can mow real grass pretty effectively with blunt blades - but I think you can come closer to the reel-mower ideal by using sharp blades.