Apologize for the initial blank reply. My beer drinking is less frequent these days and, after a brief romance with tequila, I have found that wine more suits my passions.
I understand that there are arguments both for and against DA substitution rules, and while I think the arguments against (which do include increased risk of injury, among others), far outnumber those in favor (game fitness and management), I think reasonable people can come to different conclusions, and this probably has been and should be a separate conversation.
My point highlighting the rule is similar to my issue with some other rules and decisions US Soccer has made (the build-out line, the college ID camp rules, the entire process to hire a new MNT coach). US Soccer has a bad habit of focusing on the symptoms, not the underlying disease, and then providing morphine, not medicine. Bad coaches will still make bad decisions and fail in player development, regardless of the rules.
When it comes to club (and to rec), US Soccer should be focusing on coaching education and development, providing a steady stream of training and development programs and guidelines (where have you gone, Claudio Reyna?), and identifying the best coaches and rewarding them (and their players). The should rely on the coaches and families to make decisions, and provide more tools to help them make the right ones (not try to force their desires upon them).
Ironically, in my years as a club parent, in games that mattered, when good coaches were in charge, I have seen the majority of a team play the full game, and the substitution look very similar to what the DA desires, without the need for any rule dictating it to be so.