The question is: What is a “positive impact on the world”?
Being in the public eye and like Israel isn’t necessarily a positive impact.
It’s only when someone does mitzvos that it can lead to a positive impact.
So be proud of the mitzvos a Jewish celebrities does, the things that link them to their Jewishness. But be proud of them being a Jew if they don’t behave as one is supposed to? I think that’s a stretch.
You can feel a kinship with them, knowing that we come from the same holy roots, but proud of someone not following the Torah? Hmmm…