I have always been more than a bit skeptical about reputation systems that employ so called “downvotes” or “dislikes”. Because I believe that by providing a negative incentive downvotes will oppress legitimate dissent by unconsciously leading people to either agree or stay silent.
Each time you are downvoted it gives you a negative incentive not to voice that opinion the next time. The slightest disagreement with the majority can have this effect, since it can accumulate to an overall negative reputation over time. Even if you ignore the negative incentive, at some point your reputation will become bad enough that you will be ignored or barred from further discussion.
Ask yourself, would you want to have downvotes employed universally and on a global basis? For example, would it be desirable if millions could downvote someone for proclaiming that there is no god? Obviously such a system would be really bad for minorities, and for the world as a whole.
Downvotes do not correct factual error
In some cases downvotes might cause a person to reflect on what they have written. But that will only happen if the person believes that downvotes are evidence that their submissions are actually faulty, rather than signaling that the person who downvoted did so for various other reasons than being objectively right about a factual disagreement.
Reputation systems allow for an ambiguous interpretation of the number they assign to content. That downvotes mean that someone is objectively wrong is just one unlikely interpretation, given the selection pressure such reputation systems cause and the human bias towards group think.
Even if all requirements for a successful downvote are met, the person might very well not be able to figure out how exactly they are wrong by observing the change of a number associated with their submission. The information is simply not sufficient. Which will cause the person to continue to express their opinion, or avoid further discussion and continue to hold wrong beliefs. Even worse than this, it will likely cause people who are downvoted to become angry at those who downvoted them and retaliate, causing any discussion to degenerate into a fight.
In response to this it is often argued that little information is better than no information. Yet humans can easily be overwhelmed by too much information. Especially if the information are easily misjudged and only provide little feedback. Such information might only add to the overall noise.
This problem could be alleviated if people had to actually explain themselves in order to voice their disagreement. But the possibility to downvote someone with a single mouse click discourages people to elaborate on their disagreement.
If people had to actually write a comment to voice their disagreement, everyone would benefit. The person who is wrong would benefit by being provided an actual explanation for why someone disagrees and would therefore not be able to easily believe that the person who disagrees just doesn’t like their opinion for irrational reasons. The person who disagrees would have to be more specific and maybe name some concrete reasons for their disagreement and that way notice that it might be them who is wrong, or that their disagreement with the other person isn’t as strong as they thought. Further, everyone else reading the conversation would be able to discern whether all parties involved in the discussion actually understand each other or rather talk past each other.