Fair point, but there's plenty of coast / riverbank that isn't in the middle of a major city.
The whole area around St. Mary's is a dump. I'm always surprised when exiting the stadium by the amount of derelict buildings on the river-side of the road.
Surely these would be ideal redevelopment opportunities. Well, would have been up until last week when the brexit brigade drove us off a metaphorical cliff. Now you are more likely to see property developers throwing themselves off the roof of said opportunities, but hey, that's a different thread!