Chum Eater,

Great question.
I think it depends on the river. Seems to me you just need a little more room and far more even conditions for divers and bait than you do for plugs.
I don't run divers in riffles, areas where there are a lot of bigger rocks, knarly water or when I'm fishing pockets because they get fouled too easily. It's the deeper, bigger, slower or more even runs that salmon like that seem to favor divers and bait. My .02.
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Matt. 8:27   The men were amazed and asked, “What kind of man is this? Even the winds and the waves obey him!”