|Critique as requested:
I was torn on this image.. I voted a 4, and that was entirely for the bokeh.
So, let's talk bokeh, I like the amount of blur, it suits the image well, not so much that everything is indistinguishable blur, but enough to really smooth out the background.
Except it's not that smooth is it?? There appears to be an over-sharpened look to the bokeh, especially along the white edges.
Now on to why I didn't like the rest...
Flowers are super, super prevalent in this challenge, so that means you really had a pretty high level of competition here... And frankly your flowers are just too pastel colored. The washed out whites in this image also hurt your score.
In addition to the bokeh, this looks like an image that was slightly out of focus and then sharpened to compensate.. Not good for the bokeh, or the subjects.
As a final issue here, the composition is not to my taste either, the subject is somewhere about middle, and that just doesn't suit this subject well at all.
This looks like mid-day sun? If so, that's a serious problem, as there's nothing that can mess up your shots like harsh shadows and blown highlights.
Try this-- Get a helper to hold a reflector / shade so that you get really nice lighting on the subjects..
Now, to be fair, this is still a nice picture - it's just a 4 in the bokeh challenge for me.. I don't see what I was looking for here, and you choose a very prevalent subject (even I shot a flower picture.., I however did do it as a studio shot.. Soft lighting really helps with flowers..)..
In any case, cheers, and I hope you score better with other voters..
BTW: f/4 @400 mm is extreme! I think some of what I've complained about here might well be related to the limitations of glass :)