Because outside of beautiful California, people have had to hide their grows and so we are having to be the ones doing the work of figuring this shit out in our local environments. Some people out there know what they are doing and do it well, but outside everything is different even a few miles away from pests/shade/soil/runoff/wind on and on so doing what they did might not translate to success in your micro environment.
My friend grew a bunch of cinex this year and that got hella moldy early and that is supposedly all or mostly sativa (i dont buy it). The cinex was the first strain of his that flowered tho and the buds got super huge and dense so by the time we got our first rain it was the perfect storm for bud rot. Super big / super dense buds and insect excrement seem to be the biggest factors for rot in most gardens in my area...freakn catapillars! Theyre easy to deal with but such a chore when u have to spray for everything else alrdy. Which reminds me, spray in morning before the sun hits em to avoid mold, i had a partner that swore by late evenings saying the humidity is worse than just stagnant water droplets but i dunno, guess thats for a new thread.