You have reading comprehension issues. I used someone clearly awful like Duke to illustrate a point- no one would say "oh, wrong time and place" if he got put on blast while expressing condolences. So it is a totally arbitrary line- it's ok to criticize one really bad person anytime ("fair game basically 24/7) but not a random dude on the internet who does it.
Why is there a difference? Because societal norms have been established that a set of people (the odious ones) are essentially fair game all the time. Odious includes large subsets of people besides racists- some wouldn't include the Kardashians, I would (if one them posted the same thing as Rick Jr and got told to walk off a bridge, most people would laugh). So the question is whether Rick Jr falls into the odious category. Some people think he does- we paid money to attend the school (I am going to go out on a limb and say you and Earnest T Bass aren't alumni). Miami has been a laughingstock for almost two decades. We finally had a championship caliber defense and the unqualified dunce son of the HC (who is treating a storied football program as a Mom and Pop shop) has utterly failed at his job, which he ONLY has because he is related to the HC.
I wouldn't do it, but I also understand why people would put Rick Jr in the fair game category (like a Kardashian).
If he wants to pray, then pray privately. If he wants to use the social media platform to ask people to pray for Milton, then that is somewhat understandable. That's not what Rick Jr did. He basically tweeted out, "HEY EVERYBODY LOOK AT ME, I'M PRAYING SO HARD FOR THE KID BECAUSE THAT'S THE KIND OF GUY I AM, THAT MAKES ME SPECIAL, GIVE ME ATTENTION."
He pulled a Kardashian. It is what it is.