yeah, i'd really like to see something done to address the issue, but i don't know if there's the kind of response to these injuries in the public that we're having. i'm worried that the response you see on the tachiai.org blog that "sumo is a combat sport, and people do, sadly, get hurt" is the one you'd see among the japanese sumo-watching public, which is really the only cohort that will prompt any action from the sumo association. i would have expected that kisenosato's injury and the way it ruined the career of their first japanese yokozuna in over a decade would have initiated a call for action, but who knows.
as far as what's causing this rash of injuries, i've really got no idea. i know people have brought up the issue of the jungyo schedule between the tournaments as not giving the wrestlers enough time to recover from a tournament. that definitely seems like an issue that should be looked at, but that seems like it hamper recovery rather than resulting in the injuries themselves. although many of the injuries we're seeing are knees and whatever being re-injured. i'd guess that the most likely culprit, and why this is more of a problem now than it was before, is the increasing size of wrestlers putting more strain on their lower bodies.
ultimately i have no idea, but if the sumo association doesn't initiate some kind of investigation into the issue after this tournament (and i suspect they won't) they are derelict in their duties in my opinion.