Unh...there is nothing about jig patterns, used for nymphing, that is purported ( appear or claim to be or do something, especially falsely; profess ).
They just plain work and are excellent for placing nymph patterns in the most desirable location in the water column:
I use them all the time:
Now, the next thing, in fly fishing, that can be complained about (tungsten off-beads), may be found here - but read the whole article, in it's four parts ( cut & paste - not a hot link):
http://flyfishinggazette.com/the-deadly-off-beads-part1/
PT/TB