Not so when fishing the heavy nymph for Salmon. If the fish does not take after a few attempts, we would leave them alone and come back and try later.I wouldn't presume any expertise in this area, but is it possible people give up too soon.
I fished for some difficult trout (wild browns) this year, and, they knew I was there, and refused to take cast after cast, until finally, the presentation is just right, and, click, they've grabbed the nymph.
We share similar thoughts miramichi and after a very succesful season fishing nymph style for summer steelhead in clear water I am quietly confident that this method will work equally well for atlantic salmon. I have yet to test it but hopes are high. As far as striking goes I would say definitely do it. Out of all my hook ups so far I would say there was only one fish that came towards my presentation, struck it hard and then turned away hooking himself. On all other occcasions from what I could see through the ripples the fish seemed to take the nymph as it drifted past. The line would tighten slightly and a good firm strike would have you in contact with a rocket at the end of the line. As I always fished alongside a buddy whom exclusively swung wet flies I think this is another method that will at least double an anglers chances when swinging flies just isnt cutting it.I'm fascinated by the question of whether or not someting similar to this technique might be an effective way to regularly get some salmon to take that don't appear to be otherwise catchable. You regularly see fish holding that you can wade near, that won't take a wet fly swung over them, and won't take a dry fly either. I have tried nymphs with strike indicators over these fish, but not a lot, and so far with no luck. But I'm to experiment with it more this year if we get the right conditions.