Re: abusive sensei
This is the sort of topic that has enormous potential for people talking past each other, using the same words to mean different things, and in general not proceeding from the same frame of reference. Nevertheless, it has the potential to be a worthwhile topic -- but only if people first take the time to set aside the labels and talk about what they mean by them.
Take "abusive", for example. It's not a field I work in, but I believe there are some useful guidelines that explain typical behaviors and agendas of an abuser -- and, moreover, that explain why they're abusive in context. I believe that labeling a person or behavior as "abusive" needs to be accompanied with such explanations if it's to be part of a useful discussion, and not just name-calling.
I also don't think that discussing whether persons long ago and far away are/were "abusive" is generally productive. And, you know, the same goes for "tough". It's just another label. You might like the connotation of the one and dislike the other, but it's just another label that devolves into a "yes it is" "no it isn't" pointless spat unless you define your terms.