Your #1 has basically already been adressed by Squirrel and, to a point, Xeb. It basically is just a dangerous technique to the one using it. HOWEVER. You also have to consider that techniques, such as this, were created in a time when you would study one martial art, under one teacher, for the duration of your (or their) life, or until you absolutely could not anymore for whatever reason. People in TMAs literally spent their entire lives perfecting their technique and doing conditioning to use these strikes. Now people crack open a TMA book or go to one kung fu class and think they can use the techniques to maximum efficiency, then can't, and think it's just a bs technique then.
#2 - What's it matter? If you're not in an art that trains this, then why bother trying to learn it? That's just unsafe and inefficient.