Soldiers I had in my units in the Army. They are being compensated. They aren't doing this for free. And the form of compensation combined with the fame associated with it would be more than worth it to a lot of people.
No one forced them to play college sports. No one forced them to do something where they would be in the public spotlight and criticized by fans, sportswriters, and broadcast journalists alike. If they didn't want the criticism associated with it they could have just been a normal student and avoided it all.
It would be nice if people weren't jerks about their criticism. At the same time, trying to shelter anyone from reality often doesn't work out in the long run considering they will one day have to face it themselves.