This specific treatment in post-production makes the image look like it is intended either for a postcard or a wedding album (or something similar).
Outside of those explicit purposes, I think I would like it much better if it was without the vignette. The scene is photographed with a nice softly blurred background and adding a vignette seems to be superfluous.
But that's me. I bet a lot of people would love this picture just fine the way it is...
