I was merely comparing what we do as a way of explaining, perhaps, the breeder's comment about culling them within a year. He made that suggestion because that is what he would do.
Personally, I do get attached, but it is a different kind of attachment than say, to a loyal dog of some 10 or 12...
Everyone has to find their own system of managing their flocks, taking into account their enjoyment, their egg business should they have one, and the cost/benefit ratio of the flock. Feed costs are skyrocketing and shows no signs of retreating anytime soon. Your breeder follows his plan...
18 months sounds reasonable. Many folks sell off their hens at this point. If they've been resting for awhile, the light therapy should be effective and they should resume lay. It takes awhile and you'll just have to give them time.