I agree to some extent about the graphics being great but don't consider it irrelevant or petty when people complain about the ground texture. Sure it's not the biggest deal when considering gameplay matters most, but it still matters. Especially for when you're taking pics to post on Miiverse, the ground (up close) looks awful from those screens and brings down the quality of the pictures.
It's like when playing MH3U and you're fighting Jhen Mohran, you're on it's back, the game is running smoothly but that sand blowing looks sooooo bad that it just detracts from the experience and takes something away from it.