Fish feed at different depths of water at different times. Granted it is true that they are mostly taking nymphs 0-12" from the bottom, but sometimes, like live2fish pointed out, they will take them in the middle or upper section of the water column.
I also use the 1.5x up the leader rule for indicators, but i say 1.5x from the lowest point of the leader (i.e. the point of the leader which reaches the bottom, or gets closest to the bottom). If your using weight, and no beadheads, your lowest point will be the point where the weight is. If your using beadheads, it will be at the fly.
Like the scenario live2fish described, if you are intentionally fishing a section 2' deep in a water column that is 6' deep, there is no need to have an indicator 9' from the fly, it should instead be 3'.
As for the people that are getting hung up a lot, try moving your weight further away from the fly. Usually weight 8" from the fly will result in the fly drifting 0-6" above the bottom. With every inch you add from there, your drift zone will increase by an additional inch (at least thats my theory). For example, weight 12" from the fly will drift 4-10" from the bottom, weight 16" from the fly will drift 8-14" from the bottom, etc. Keep in mind these numbers are assuming that your weight is indeed bouncing along the bottom, and not suspended a few inches above it.
I typically use a tandem nymph rig with 2-3' tippet between the nymphs. I apply my weight in here, and place them different distances away from each fly. I can place one weight 8" from the dropper, and another weight 14" away from the top fly, so that I get one fly probing the 0-6" water depth, and one the 6-12" depth. If I see that the 0-6" depth is getting all the strikes, I'll adjust the weight on the top nymph so that it drifts in the same 0-6" area.