I critique. Critiques are meant to be harsh, so you can learn from them better. If I see something that really stands out to me then yes, I compliment it. But mainly I give constructive criticism so other people can further their own knowledge.
To me, that shot looks like it was already maxing out the camera's ISO, then you ran it through a sharpener. In better light that would look a lot nicer, and I bet you could get almost the same photo, but without the ugly grain.