I get the feeling you were going for simplicity, and that you did achieve - just does not have anything to grab my attention. It is just my opinion, but I feel a photo should say something - tell a story or convey a message of some sort. This seems to be the type of photo shot just to meet the challenge - not shot becasue you wanted a phot of this to hang on your wall or look back upon later. I have done that myself in past challenges and try to avoid that now. The colors in the sky are very pretty.
There's no detail or significant line or shape that draws the eye to continue exploring this branch. Anything, a bird for eg, would have resolved this.