To answer your question, I do use blur in my photography both from intentional movement of the camera and from regular old narrow depth of field play. I do not exaggerate it in post processing. I have used other elements of post processing like hue and saturation adjustments to alter the feeling of the blur. I accidentally shot a heron at too slow a shutter speed and did wind up processing and keeping the image. More for the background blur than the blur of the bird, however. The experience did not lead me to purposely recreate that effect. There are times I purposely shoot out of focus to create patterns and shapes. So, there are degrees of blur. I often think of blur as bokeh--the supporting aspect of an image that has a clear subject. I regularly participate in a bokeh thread on Flickr that discusses and analyzes the artistic intentions behind the use of bokeh in an image. You might like the heron shot:
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I also like to shoot reflections in ponds sometimes devoid of any solid feature. The slight ripple will create an impressionistic effect I like.