As others have pointed out, uploaders had the ability to block voting entirely, but couldn't adjust visibility of positive/negative votes separately. There's a huge difference between a video with +10k/-10 and a video with +10k/-100k. Displaying both identically gives a deliberately false equivalence.

I suppose we still have upvotes as a percentage of views to fill in some of the gap.

True, though that still makes it ambiguous whether content in a video is heinous, or merely boring.