Downvoting is to desperately needed that Twitter users invented their own way: a ratio. To those that don't know, an unpopular tweet will have many more comments than likes, which is considered downvoting.
Thanks for explaining. I always thought it was that a reply to the comment got more likes than the main comment.
It's also that. In general, getting "ratiod" is when two metrics about any given online posting have a ratio that is on the (perceived) wrong side of 1.