IMO, zerosetback is a fad.

for me, it's the kalloy uno seatpost that has 30mm of setback.
I'd rather use VO grand cru, but it only comes in 27.2mm, when my bikes need 26.8mm, 28.6mm, 29.6mm and 34.0mm.
well, I can use a shim for 2 of those sizes, but at half the cost, kalloy uno offers more bang for the buck.