It has similarities though, as pointed out in orher comments. For one, a user might be more careful with downvotes if they are afraid of negative consequences e.g. harassment. With piblic votes, there would therefore be a bias towards upvotes and and people abstaining from downvotes, i.e. less interaction in total.

Downvotes serve a purpose today, letting us quickly scan which comments are controversial or even harmful to the conversation. I, for one, usually sort most threads by votes and then skip the comments with many downvotes but for controversial topics, I instead seek out the comments that have both many upvotes and downvotes.

These would be harder to find given the above bias.