Looks like u got all the info ya need so ill give more of the same lol. In short its because people are impatient, but other reaons are medicinal properties, height restrictions, or like me I am perpetual with a "backbokne" strain. Which basically means there is 1 strain that I know inside and out, as well it has the main properties I look for to aleviate my problems, therefore ANY strain that goes into my garden must finish in 10 weeks to keep things going according to plan. This limits me to indica and indica dominant hybrids. It is also a "backbone" in the sense that I know it well... Too well. And therefore if I bring in a new strain or things go south I KNOW I will always be pulling consistent quality and quantity yields with which is important to have as a medical grower with people depending on the fruits of your labor. But yeah main 3 will be flowering time, height restriction, and medicinal properties, typically indicas are higher in cannabinol(cbn) and cannabidol(cbd). These compounds are more directly linked to aleviation of pain nausea and cancer symptoms (also been shown to be a great anitpsychotic, anti-epileptic,vasorelaxant, antispasmodic, and even anti bacterial) than thc which is more profound for its psychoactive properties (cbn and cbd are non psychoactive meaninf smoked alone they wouldn't get you high. Though they do play an important factor in overall stone) thc also has medicinal properties most notably its use as an antiproliferative, anti pasmodic, antiepileptic, anorectant, and as a bone stimulant. In the medical community ( around here at least) sever pain decresed appetite and cancer are the more common illnesses, meaning indicas generally will have more of the medicinal properties they seek.... Ok I think that's enough lol.