Squirrel hair, marabou tails, dumbell lead eyes, wire/lace ribbing, etc. all need more than 2 turns to wrap securely.

A lot of natural materials are not durable so the tie on isn't the weak point and there is little need for greater security than a turn or two.

My personal opinion is that a quality, well engineered fly pattern needs to last around 20-30 fish of good size (i.e. 2+lb trout), or 10 steelhead in the 7lb range, etc.