I think it is the color choices. It doesn't help, but I guess they have to use those colors for the type of environments. Talking about the 1st and the 4th pic.
Also, anyone playing Monster Hunter for graphics is playing it wrong. :p
Sure but nothing is lost from having better graphics. They could just make a few tweaks to gameplay and have it looking beautiful. Some of the WIi-U MH looks beautiful, specially the monster detail and places like Misty Peaks but some of it also looks very poor. It does not get in the way of the great gameplay but I still get a little annoyed when I see those images at the end of tunnels and those 2d animals roaming the hills. Amazing to see that detail now in the Wii-U version but it looks poor overall.