If someone studies botany they will learn that plants do need periods of darkness in each 24-hour period to perform all their functions fully. That is a proven fact. Plants produce a flowering hormone and in some plants it will be destroyed by even just a few minutes of daylight longer than what would give them a period of darkness that is long enough. When that happens, they will not flower because the needed hormones were destroyed and will keep being destroyed when made unless the length of the period of darkness is increased.
The thing is just how much darkness does any type of plant need and then in cannabis how much darkness does any specific strain need? No one seems to have a precise answer to that question.
Cannabis, for all the headaches it can cause, is really an easy plant to grow, it is very vigorous and it can and will survive in conditions other plants would not survive in. Because of that over time so many 'home experiments' have been done and plants did not die and at times for various reasons some 'home experiments' seemed to have been successes so they were told and then others emulated them. Most times they were nothing more than beliefs.