A few years ago my wife and I had that discussion. She did not like that I was blurring everything. So I took a series of shots at different shutter speeds and asked her which she liked better. She ended up liking the blur better (just not to much). In the end, the fast shutter speed shows all the water drops individually, and the water looks like a chaotic mess... no order. That is not how ours eyes sees things. But to each his own I guess.
So here are some examples... these are not going to win any contests for composition, but were intended to show motion blur at different shutter speeds. These were taken a few years ago with a 7D and the old version of the kit lens (before IS) EF-S18-55mm f/3.5-5.6. They have shutter speeds ranging from 0.6 - 1/125 seconds. The shutter speed (Tv), aperture (Av), and ISO setting are shown in the titles of the image:
Tv0.6-Av22-ISO100 by westmichigan, on Flickr
Tv0.3-Av22-ISO100 by westmichigan, on Flickr
Tv1/50-Av8-ISO400 by westmichigan, on Flickr
Tv1/80-Av8-ISO400 by westmichigan, on Flickr
Tv1/100-Av8-ISO800 by westmichigan, on Flickr
Tv1/125-Av8-ISO800 by westmichigan, on Flickr