The public who sits back allowing every word, mannerism, and gesture of the celebrity to penetrate their emotions will usually believe what they see and hear. Rarely, do fans question or challenge a well-written script. As for busy folks, they have too many other things to do to analyze the double-speak that goes on during celebrity interviews and news coverage.
Now if a celebrity would be so bold as to speak openly about an issue, without waiting for the greenlight from handlers or share secret knowledge about someone or something, then they run the risk of being publicly shamed. They also miss out on profitable future opportunities. In addition, individuals around them unexpectedly are fired, wounded or even murdered. Like a child being disciplined by a parent, so to a celebrity with handlers.
In closing, if you should ever wonder why some celebrities won't use their platform to help others, know that unless it is an issue that one or a team approves or can monetarily benefit from, there is no reason to jump on the bandwagon and talk about it.