And now I will take an opportunity to stand on a soapbox. I agree they are a good thing. Normally, an MIR is filed because someone observes someone else, often a newcomer, violating WikiTree standards. Usually, it is not a particularly adversarial process.
When it is an adversarial process, I don't think it works so well. The person who files the MIR is not told what is happening, and speaking from personal experience, that leads to confusion and sometimes worry that the process is unfair. In my own case, I thought the MIR would result in a mediation, with both parties (the complainer and the one complained about) being consulted about all steps in the process. That does not necessarily happen. It is not always transparent.