The cannabinoid profile is genetic, as in the plants genes determine which terpenes it produces at (more or less) what concentrations. And the parent plants only pass on what they have to offer.

Its just that the traits we visually see and identify with a sativa or indica "genetic line" like leaf type, growth structure, nodal spacing, and flower time, are not genetically linked to the cannabinoid profile. As in, these traits are equally dispersed genetically in the overall population, and you can really only rely on parent to child genetic inheritance, not any sense of trait linkage from a lineage of a suite of traits.

Maybe once upon a time they were. But cultivated weed is so well interbred now that any history of genetic linkage has long since been broken.

It really really doesnt help either that growers and budtenders do not use those words the same way. A sativa in the greenhouse is not always called a sativa on the shelf at the dispensary.