I really don't think that will roll over well, especially those that easily take things personally. Not everyone is mature enough to accept/respect that someone may not agree with what they have to say and that could mean unnecessary drama. Not to mention, there are some open downvoter's that do it just for the fun of it and I can imagine that would take some fun out of it.
Ideally everyone would get along and respect one another's points of view whether we agree with them or not, but I don't think that would be a realistic expectation. Blocking rates might skyrocket though.
Yes, good idea i use to go on this old site called BluBet people used to heckle other peoples opinions/ questions finally the owner came out with a feature to stop the heckler anyone who downvote ( heckled) they got it in return.