This seems like the wrong target to me. Why not go after the user?
If there's a user that is going around disliking a ton of videos, especially on a single channel, and/or without watching some minimum time or % of that video, it seems likely that user is being abusive; so perhaps shadow-ban that user's votes?
Similar with new users.. disallow use of dislike completely until they've been around a while and built up some reputation/history (by watching, upvoting, etc). If the user is possibly a bot (I assume there's algorithms to determine confidence of bot vs real user), require more verification.
I'm sure there's a reason they're not taking this approach, but I find it hard to believe they're choosing they way they are based on the reason they're giving here.