.
Your experiences have lead you to believe that those following the non ITF standard suffer no loss. My experience is different. If I asj\k why they do something a certain way, it's not that I have an issue because their reasons are different than mine, it's because often they have no reason other than "That is what my instructor did." To be fair, I have run into ITF people who were taught or learned this way as well, but that is not the fault of the system. Reasons are spelled out most of the time. Reasoneable minds can disagree as to whether the reasons make sense. I have issues with some of the rationale. But it least it's there to consider. Other issues are loss of detail. An example might be: No idea what the diffferences are between a Side - Piercing, Pushing, Thrusting, Checking, kick all of which is contained in the patterns. Not having these differences dilutes the art.