I take your point, and very much agree with the last paragraph, but I will say as well that a lot of it also has to do with the delivery. As a child who participated in a number of sports, quite often being told the equivalent of "Move your lazy butt" was far less serious than "If you're not going to take this seriously, leave the class because you're disrupting those who want to work". Usually, we kids were giggling at the first one and its equivalents, because it tended to be delivered in good humour, but if the instructor/teacher/trainer used the second, it wasn't funny any longer, and it was often delivered in tones intended to crush. And those were the rebukes that stuck and stung and made us feel worthless, especially when coupled with the cold shoulder after that. I had riding instructors who were really good at that, and I have less than happy memories of their lessons.
It may also have been something to do with the teaching culture from the time and place I grew up. It wasn't limited to riding. Like, we had a ballet teacher who was horribly emotionally abusive, but she never swore at us or raised her voice, just shredded us one by one by one. She played favourites, but the moment anyone failed to perform up to her personal standards, she would drop them like a hot potato, and write them off, ignoring them in class unless she had something critical to say. She wrecked our entire class's confidence and our love of dancing, because of her insidiously abusive approach over the years. But there was a male teacher who shouted a lot, called students rude things, threw things, and was generally loved, because somehow he didn't destroy your self-esteem when doing that. It was a reflection on your performance in the moment, rather than a judgement of your entire worth as a dancer. Though, that said, he could be terrifying at times, and I do recall one rehearsal where he picked up a chair and hurled it at the studio floor so hard the chair broke, and we all sat in petrified silence. So, yeah, that was the downside to his temper.
So I think it's more complicated than the vocabulary used - it's also the context, the tone, the manner in which it is used, and the behaviour of the instructor that accompanies it. I have not a clue how Eteri teaches, but maybe she's one of those trainers who will yell at you without making it personal, or maybe she isn't. And also, as someone who is now a teacher, what works for one student may be intimidating and unkind for another. Some of the students I've taught like to be teased, some hate it; some of them will respond well to a sharply barked instruction, others will crumble; some flourish when praised and encouraged, some find that phony; some like a lot of support, others prefer to be challenged. Every one of them is an individual, and a good teacher will find a way to motivate and encourage each one according to what works for them - though in group settings, this is not always possible.
Anyway, instruction/teaching/training is more complex, more individual, than is often realised, but it should be about building the student, not breaking them down.