Several posters have touched on what I believe is the key point here. What you are calling "subtle" images are images that don't have a lot of initial impact. If you are selling beer, or engaging in competition, you need to capture the attention of the viewer in the first few seconds. That takes impact, and subtle images aren't going to do it for you.

There is a place for subtle images. They tend to "grow on you", and you can hang them on the wall and they will feel very comfortable.

Or, a collection of images displayed together can be made stronger by the addition of a few subtle images, even though those images won't work very well in a stand-alone situation. In this situation, the subtle images tend to act as mortar, bridging between stronger images that are not totally compatible with each other.

As Michael noted, subtle images are wrong - - - which means that they violate one or more of those rules that Kodak published 100 years ago and that photographers have been following religiously ever since. The same rules that the best photographers have learned to creatively break.