Fiberglass repair is quite well understood. Part of the problem is some early turbine blades used wood cores which are incredibly difficult to repair. But if they used synthetic cores (coosa board) they'd have a stable core to repair for centuries. Maybe they figure it costs more to repair than to replace, which could easily be true. Either way it's not a huge problem, look how much the average American tosses in the trash every week. But I'd still like them repaired