Because the color blends with nature rather than contrasting and generally looks faded, dull, and ugly. Eeesh.
Asking this question was a mistake. Now you’re in danger of being convinced, and subsequently enjoying your new light a little less 
[quote=cainn]
Exactly haha. I didn’t even understand or care about tint until I started reading here. Now most of my lights are NW and I plan on switching some of my other lights to NW.
Green tints just look very unnatural to me and I prefer a more natural/neutral tint.
I can tell the light is a bit green but, I am a slightly color blind. It actually helps me see some yellows and reds better. 
I do not like L.E.D.’s that have a purple tint. I have trouble being able to see colors with purple light. The L.E.D. might have a longer life having a little green. I think the first L.E.D.’s that were used in consumer electronics were red, amber, and green.