I'm going to add a perspective I have had to tell players over the years when I gave them the same advice I gave young guys going into boot camp. There are coaches like this out there. There used to be more.
My son's freshman and sophomore years we had one of these old school coaches. He was vulgar. Screamed obscenities at the kids. One of his favorites was to grab a bat out of the batters hands during BP and throw it as far as he could into the outfield and make the kid sprint after it. From the outside, it looked awful. I, however, had gotten to know this guy on a personal basis. You would never have known how much he cared about these kids from his demeanor on the field. I once watched him completely humiliate and berate a player at practice and then, less than two hours later, was with him while he sold a college coach on the kid in glowing terms. I'm not sure this kid ever knew what the coach thought of him. This was his style of coaching. It was his style. I didn't agree with it, but I never saw him put kids in physical danger. Of course, it was somewhat psychologically a problem and wouldn't fly in almost any other area, but this is nothing new in sports.
One place it does fly is the military. I have counseled kids with coaches like this to understand what such actions do and don't mean. I tell the same to kids I know going into the military. It's just a pre-planned strategy they use. It's nothing personal and there is almost nothing you can do to avoid it. This is how I got through boot camp. I simply understood. Once you understand that it's not personal and not a reflection of actual hatred toward you, the hard part becomes actually trying not to laugh at what then just seems like a comically absurd, over-theatrical style of motivation.
Now, maybe your kid's coach actually does hate him, but it's unlikely. More likely, this is just what he thinks works. Now, coaches who put kids in harm way are a different story. It's an old saying with coaches like this that you shouldn't worry when they are screaming at you and berating you - it's when they stop and ignore you that you better worry.