If there is a wonderful shared access path such as the one you mention then it is a perfect option.
I'm puzzled as to why you think its a perfect option. Before the magic blue signs were put up it would have been exactly the same bit of pavement in every way but not a suitable option according to you. They change the legality but they don't change the physical layout or the problems of interactions with pedestrians in any way whatsoever. So what makes one a perfect option and the other unacceptable when the actual pavement is identical?