Points well taken, but maybe a bit harsh.
Thanks. Yes I agree I was being a bit harsh to both OP and the players. But I think the main point I want to emphasize is that, we should not cry afoul so quickly and jump into conclusions, or worse, call for changes that may not even be the cause to these issues.
Looking into Marin's injury history, her knee has been surgically reconstructed. It will never be 100%. Add to that she has injured it several times since.
I am not a doctor but I feel after you suffer a major injury like Marin did, you often end up compensating it your gait and steps, which then tends to lead to injuries on other load-bearing body parts, as happened to Marin.
It was also her choice not to wear some sort of brace given her knee injury history. You look at how much taped up ASY's knee was throughout the Olympics. So you cannot simply just blame how tough the game is when the players themselves opt not to take precaution.
Having said this much already, I will offer some form of suggestion in how I think it could be fair for players and incentivize them to play. The BWF could abolish the penalties as well as the mandatory tournaments players need to participate in. In exchange the points system for ranking can be amended slightly so that the difference between winners, runners up, semis, quarters, etc. are not so wide.
Using a typical Super 1000 tournament as an example: Winner gets 12000 points, runner up gets 10200, semi gets 8400. My system would instead be winner gets 12000, but runner up gets 11200, and semis get 10800. The actual points you can gain doesn't matter. What matters is that the points are closer than what they currently are.
The idea being you are allowing the top players to pick and choose how often they want to play, but in doing so, it will mean allowing those below the ranks to rise faster and pose problems in seeding and matchups in tournaments down the line. You might even lose your rankings by skipping tournaments. Basically, you are incentivizing players to keep playing while also not penalizing their need for rest and recovery.