It's easy to imagine how "Jews run Hollywood" is used (well we don't have to imagine; we know, and examples are probably not hard to find).

OTOH, unless we're saying Jews in Hollywood, or George Soros, get a free pass just because they happen to be Jewish (assuming Soros even is; I suspect most people who criticise him don't know), then we need to be careful of silencing legitimate criticism by falsely labelling it anti-Semitic.

That's the point though: it's quite difficult to conceive "lots of Jews in Hollywood" as a criticism rather than a pretty anodyne fact unless one is making "Hollywood is liberal because Jewish conspiracies are using it as a tool to push their agenda upon an unsuspecting public" which seem rather more deeply rooted in anti-Semitism than reality