With the big Loblaws, the LCBO, the office tower at 1 Yonge, Corus, and that nightclub nearbye I don't think Sugar Beach is particularly isolated.
The bigger picture, I think, is that the waterfront promenade is an attraction unto itself. The idea that folks must be lured down there - that without the presence of commercial "attractions" they may not go there - strikes me as a misreading of how waterfronts like ours can work. Perhaps Sugar Beach is an example of that evolving process. If Toronto is defined as a city by a lake then the point at which the city meets the lake has a strong natural attraction, is a unique experience, and being there is an end in itself. Better not to try and spin it as something it need not be - a "Queen's Quay South" for instance, or an imitation of a shopping strip like the Danforth, or wherever.