Assuming this is HS...
Tough spot. A few things...
To what extent are you certain that this is an ongoing thing? To what extent are you certain that the majority feel this way? I see your son plays other sports... how drastic is the difference between the other coaches and this one?
I'm trying to determine if this is clear cut and all players and parents involved would be in agreement with the assessment. If so, then there are probably some courses of action that should be considered. You said he expects more out of your son. So, it sounds like your son is one that holds the most respect from him if there is such a thing. It may be helpful if your son was able to ask for a sit-down with the coach and respectfully express that he feels like his teammates are struggling to perform to their abilities because they feel like they are constantly getting beat down and can't seem to do anything right by their leader, despite efforts. Respectfully express that they are trying to play hard for him but having a hard time enjoying playing the game because everything is always negative. If your son feels that this would not go well and put him in a bad spot, then there are other options. Again, if there is certainty that there is pretty much unanimous opinion on this, a respectful comment to the AD, preferably by a parent that has some decent relationship/dialog with the AD, would be a worthwhile starting point.
With all this said, some of the things you mention suggest that the coach is particularly unhappy with this particular group's overall efforts. If he is mostly right, then maybe it is the players who need to be making the effort to turn things around. We are unable to see what is actually happening so hard for us to tell.
To some of your other points...
There are several valid reasons why a coach may not post stats. Don't sweat this one. Your son is not going to be recruited or not recruited based on HS stats being posted or not.
"hit the top half" - this is certainly out the window as a a mainstream hit teach but it can be appropriate situationally (hit-and-run, pure speed guy, etc.). It sounds like your son is interested in continuing his playing days beyond HS. The more important takeaway is what Dominic alluded to... your son won't necessarily be able to pick his coaches going forward and he is certain to run into instruction that conflicts with what he has had in the past and/or what works best for him. He will have to learn how to navigate these instances. My preference is good open communication and working toward best resolution. Others will suggest differently. In any case, he will have to love playing enough to be willing to work through these inevitable issues if he wishes to continue on.
Venting here is generally a good idea... much better than inflicting negativity among the other players and parents and/or your own son. But, again, if you are really confident that the problem is clearly affecting all, I would look into those action steps.
Best to you.