Why? I think it's great. The texture of the cactus is great and the command of depth of field is as well. If I was going to be picky it looks like there might be a bit of over sharpening or aggressive clarity on/around the boulders on the right, and I might crop a bit off the left so you have one sweeping line from bottom more left through top right, instead of sort of "center left to top right" like it is now, but that would be looking for something to change - I don't think it's "necessary."