Maybe not covered, but there is some merit in this:
What is the point in learning something you cant do? If a martial art is comprised of activities you cannot physically do, it is worthless for yourself.
I swear there is a proverb for something like this.
But there is a opposition in similar line to it, that you think you are doing something wrong is why you think it doesn't work and you doubt your ability not the actual technique itself, which can be flawed. In general with these things, some things dont work and you think its yourself and your ability not the thing in question, many areas of life are like this.
More of a response to the theme of your thread than its actual content however, or the literal point raised in the title.
Also the palm strike one is news to me, the only point i saw for a palm strike is, it puts your hand in danger as does a punch. (which is true) and generally might have a little less stopping power to it. Never seen someone say its bad because you can hurt your hand unlike a punch, rather you can hurt your hand in both and a punch has more stopping power. Different ways you can hurt it, you basically risk damage no matter what you do.
Doesn't mean it hasn't happened just haven't seen it.
Also the context for many things isnt addressed, it makes bad techniques look like they work and good techniques look like they dont work. I dont recall seeing the bulk videos of you tube really explaining the context of something which seems to be a issue in martial arts, the context is left out when it should be included. thats the running issue with most systema videos, no one has explained the context in it, so you cant really form a proper opinion until you learn the context, its conjecture basically.
No fault of a observing party it is the making party not explaining the context clearly enough or at all. (either out of not knowing it, their audience not being laymen but people who do their style or just forgetfulness/lapse of thinking based on their audience) how ever if they have any experience they are going to use what they learnt from that to try and make something work with how they learnt how to do it or in the context they learn it in if none is present or clearly relayed.