"These folks feel it is their 'duty' to 'save' the world from whatever they don't like. Gee, thanks guys."
The difference between celebrities and politicians for that matter) and most people in this regard is that the celebrities have the stage, coverage and money to get noticed and have influence.
That is the way the world works, for better or for worse. Best to just deal with it as best as possible and move on.
Politicians can be voted out, at least in theory. Celebrities? I guess you can stop buying what they are selling and relieve them of their fame and have the same effect, but if you like their act, that ain't likely to happen either.