It may have something to do with the direction of the current/tide. A few years ago, I was fishing the bridge as the current was heading to the south. Most everyone was fishing the south side. Maybe this was to keep from losing their rigs and lures under the bridge, since the current was carrying them away from the bridge. I went to the north side and let the current carry a carolina rigged pinfish under the bridge. Within a couple minutes, I caught my first striped bass...about 7-8 lbs.
PS: if you do fish the bridge, it may be a good idea to carry along a drop net, or at least be prepared to hand line a decent fish up to the bridge. In the excitement, I hefted this guy up with my brand new Penn Legion rod and ended up snapping about 10" off the end of the rod.