Controversial videos, or those by controversial creators, are the ones that get brigaded. If you're inside a filter bubble and can't see a dislike count how will you know what you're looking at is controversial? Yes, the ratio is not representative of the general population but it's the signal that matters.

Would you rather not know something is controversial? What mechanism would you prefer for nudging people outside of filter bubbles?

I'm happy to be generous and consider all videos with heavy dislike ratios as victims of brigading and not of public sentiment.