|Howdy from the Critique Club!
This a very nicely composed image. I like the use of negative space, the framing of the flower, and the angle from which it is photographed.
The focus on the petals is just a tad soft, but soft in a way that doesn't negatively affect the image quality. I am especially fond of the lighting of the flower itself, which is soft and adds a slight glow to the yellows in the bloom. The DOF you have used works well, leaving just enough blur on the stem and leaves, but not creating a blur that causes you to wonder, "What is that green stuff?" I might have been inclined to use just the one stem with the bloom, and either moving the other stem or editing it out in post, but it's not too distracting as it is.
The background, with the subtle shades of purple, is soothing, yet the lighter areas are a bit distracting, slightly overwhelming the soothing nature of the rest of the tones. That isn't to say that the background is bad...it's not. It could be even more dramatic with less intensity in the lighter shades, IMHO.
I would imagine that the voters during the challenge found this image to be less "purple" and more "flower." The purple is very subtle, and many voters probably wanted to "be hit over the head" with purple rather than appreciate the finer details of the color. In addition, flower shots have gotten a bad rap lately, but for the life of me I don't know why. It's not easy to take a beautiful flower picture that works as well as yours. You probably suffered from low votes from those that dislike flower shots of any kind in any challenge, which is a shame.
This is a nice image with many positive attributes and some which could be made even better with minor adjustments. If you have any questions, please feel free to PM me, as I am learning all the time as well! :o)