Dirk Hanss wrote:
2.) Suwari waza is a way to fight on groundlevel and avoid lying on the ground (newaza), being unprotected against additional opponents.
I personally don't think it's particularly effective as a ground fighting strategy. Most of the time if you can get to seiza you can get up altogether.
OK the other arguments are accepted, too.
The injuries are to be taken seriously and I still wonder, how millions of Japanese and other Asian folks can sit for hours in seiza over 70 years without having these problems and our knees degenerate after a few sessions of suwari waza on soft aikido mats.
Are these genetic differences or should we only force our children to move more on knees in younger years?
My guess is that there's a difference between sitting down to eat and talk and occasionally knee walking from here to there, and doing hours of technique involving constant movement.