unless you are working with clones, this is expected. Althrough this extreme of a difference can be blamed on the breeder, imo.
most of the 'breeders' out there only learned through trial and error and refuse to incorporate a geneticist or plant biologist into the fold and do it better. Isntead we are stick with an amish-level of processes and related behaviours. Superficial understandings, and false extrapolations based on feelings and not evidence.