The lineart is extremely rough in the bottom half of the image, especially. Beyond that, the image is a fairly generic "facing the camera" pose with no background, which is the sort of image that needs to sell itself on either above-average detail or excellent shading... which it doesn't have.
That is the purpose of the moderation queue: To whittle down the chafe to the wheat so that only the 'elite' of the images are on Danbooru. Go search a tag on Pixiv or even just DeviantArt, and the 'elite' images people actively want to see are drowning in a sea of 'pleb' work.