I guess I must be of the old school since many of the Shihans who have visited my dojos have often said that the feeling in my dojo reminded them of the old "Hell Dojo." But we have never really had a lot of really bad injuries (my apologies again to your son for his nose, Chuck
). I have always tried to follow the idea that harmony meant that if someone wanted to practice so that we knocked the snot out of each other, we both practiced in that manner. However, if someone needed to practice a little softer, we also did that; and learned from both types of practice.
As I get older, I suppose I have gotten a little softer, especially since a lot of my students now are starting at their senior ages.
I found the best answer for why not practice hard all the time? You do that and nowadays, most of the students will not put up with it and you don't have a viable dojo since we no longer have the support of rich sponsors like they did in the old days (well, most of us don't and I have to be my own sponsor these days).
Yet, I still work as an Aikido professional with law enforcement and military so I have to keep up the hard practice as well. If I don't, I will be injured by those youngsters from those professions that want to test me or those from the other martial arts that also want to test me. I also find that if I don't have the hard practice, I get bored (some people have said I have a sadistic streak and maybe they are right).
I haven't come to a satisfactory conclusion on this matter other than to choose who I practice hard with. I try to do it in private so as to not scare away potential or existing students.
I can't start them right away with hard practice with most of them since they are not used to it. However, I must interject at this point that I now have one dojo where this is not the norm. I just came back from doing a seminar in my Jamaica dojo where most of the students are at least Nidan from Karate or Judoka or semi-pro boxers. Boy, it was neat, like being back in one of my old dojos! We practiced without mats on a wooden floor and people were slamming each other all over the place! Now, I must admit, their technique was not very good and they were all using too much muscle power rather than technique, but their spirit was fantastic! It reminded me how much I missed that type of dojo.
Yeah, surgery,pills, and all that are now part of my life but I certainly wouldn't have given up the memories and the learnings from the old Hell Dojos for the anything.