Fruit for thought and nothing more; so don't read into it.

It's possible that in their way of reasoning they thought that the render was excellent, good or whatever. The residual fact remaining is that compared to all other images that they viewed, it only rated as a 2 or 3. When I was in school I was graded on a system called DEPICT also there were ability levels or classes such as beginner, intermediate, pro. Here is what DEPICT stands for

D was detial
E was eveness
P was proportion
I  was inking
C was color
T was technique

Each letter was graded and awarded. Here it's just a flat 1 through 5 reward system. 

How do you think your work compares with all the images out there? Is it 1 star material or 2 or 3 or 4, but to give yourself a 5 star rating in the gallery of fantastic images presented here is, well you know your work better than I do. You decide where you place. Just my thoughts on the matter and yes your is pretty "dang" good. 1 because I know you made it yourself in some cases where as other just buy and pose. Later,