|Hi Pall, welcome to the Critique Zone!
It's an interesting shot - not entirely to my taste but that is quite subjective. I would have expected a shot life this to do better on DPC, so here are a few suggestions (nothing more!) as to why it didn't.
Technical: The aperture seems a little open for a shot where you really want front to back sharpness. Given that you want a long shutter, would tightening it a little not have helped? I also agree with the comment that the shutter is not quite long enough - the water is blurred and interesting but not really silky.
Artistic: This really is completely subjective! I'm not sure that this works for the challenge. It's quite busy with very different structure in different areas, bright sky, dark rocks, bright rocks, blurred water. It's like a mash of different styles in one shot. Also, the rule of thirds is almost applied, but not quite so that it looks like an oversight rather than intentional rule-breaking.
I would have been tempted to make this b/w to remove at least some of the clutter (the colour) and 'minimise' it a bit, other than that I think that it would have done better in an FS, but even there it is not up to your usual quality as displayed in your portfolio.