But I don't like the word "reputation" as it goes against the idea that people who are new might have good input too. Using reputation as a discriminator is very much like committing an ad-hominem fallacy. But perhaps that's the best we can do.
A big problem is that an apparent new contributor may not actually be either new, or even a person. Only then can you determine that they're not somebody you've previously assigned a negative reputation value to.
(mind you, this is not at all sufficient; a major problem of the present day is people tweeting abuse from positions of power under their real names)
https://en.wikipedia.org/wiki/Reputation_system
But I don't like the word "reputation" as it goes against the idea that people who are new might have good input too. Using reputation as a discriminator is very much like committing an ad-hominem fallacy. But perhaps that's the best we can do.