Shepard's Citations is a citator used in United States legal research that provides a list of all the authorities citing a particular case, statute, or other legal authority. The verb Shepardizing refers to the process of consulting Shepard's to see if a case has been overturned, reaffirmed, questioned, or cited by later cases.
This is a valid point, but it's important to note that it only applies when using aggregate citation counts as a rough proxy for importance within a field. That's useful for prioritizing what to read but not for assessing the validity of any given result (of which there are often quite a few, at least in the life sciences).
Within a given paper, it's not at all uncommon for the authors to explicitly call out some detail from another study as being incorrect in their view. That doesn't mean that they necessarily agree or disagree with the rest of the cited work though.
What I'm getting at here is that negative citations would likely be far too coarse to be useful in practice. It's relatively rare that a paper outright disagrees with an entire work.
First, you would be centralizing the ability to "cancel" papers. One bad member of the board could wreak havok. Simultaneously, people in charge of the database would be constantly bombarded by pleas (not all of them honest) to revoke this and that researcher's paper. So it would be bad for both sides.
You could get away with something like Retraction Watch, but you'll always be behind - you could keep track of which papers were retracted (which is already a lot of work), but not every paper that needs to be revised is retracted.
I guess figuring out a perfect system for deciding which ideas are right is hard.
Example off the top of my head: Don't have one board decide which papers are cancelled. Have multiple. Have git repos with lists of cancelled papers. Have a process for finding which papers are flawed due to citing cancelled papers from a particular paper. Have browser extensions that tells you if the paper you're opening is carrying such flaws. Allow user of such extension to pick which board they trust. Have the extension link to a discussion about why the paper is cancelled. Give ability to challenge such claim in the open. Etc etc.
I'm sure many more such ideas can be found. The problem is probably rather funding of such system or if whoever funds it would have the right incentives to begin with.
I have no affiliation other than I have met the founder and think the product is cool.
It's rotting on GitHub, never managed to drum up enough interest...
WoT could work exceedingly well for a decentralized replacement of Facebook... though at that point there's also the issue of competing against a walled garden with moats and most of the population already inside.
In my mind it would be some reddit/Wikipedia kind of thing where advice and understanding would be debated using some formal language elements based on rdf or whatever to build up a knowledge graph usable inside applications.