In my opinion, I think this effect actually works for this composition. Most shots blurred in this way just look like a mistake, and not artistic at all.
I think it works because the lines are not too “shaky” looking, the exposure and contrast are proper, and the balance of elements create a flow for the eye to travel.
I would suggest going further with these shutter speed effects for a more creative edge. Effects can be created by zooming in or out or spinning the camera or combinations of both. Here’s a post on how to do the zoom effect, and here’s an example of the zoom+spin effect.
For best results with any shutter speed effect, use a tripod.