Think the answers here depend on how you define " tough". There’s a difference between expecting a student to follow directions and take the whole thing seriously and a nasty, mean, abusive, sarcastic and/ or demeaning approach. IMO, all nasty, mean, sarcastic and/or demeaning trainers belong in a seperate category, not lumped in with the ones who are tough because they are passionate about getting their students to succeed.
I had tough teachers who did not want to hear a bunch of excuses and got called out for that, sent to the end of the line but it was something they knew I and the horse could do and it was never personal. Any rider making a mistake was corrected in front of the group, nobody was singled out, it was part of the class to learn by watching others mistakes. Once was kicked out of a lesson but only to brush the shavings I didn’t bother to brush out of the tail, small detail but something that was often clearly communicated as unacceptable. It was embarrassing but never personal and it was in my control to avoid being embarrassed. Got what I asked for, never skilled over details again. Even today.
Ive had a few lessons from the mean, sarcastic, insulting bully types but not many as I never repeated with any of those. Never cared for the old cavalry approach, What makes one think the way they treated 18-20 year old males would be the way to treat 12 year old girls? Never got that.
Anyway, tough doesn’t mean being a bully. Looking back to when I started taking lessons, circa 1964, I now realize more then one of the nasty ones was drunk. Seen examples of that recently too.