The myth of moral equivalence [View all]

There can be perverse attempts to "contextualize" human failings by decontextualizing. One version of this goes like this.
-People commit crimes.
-Institutions cover up criminal behavior.
-Therefore all people who commit crimes and all institutions who cover up crimes are all morally equivalent.

To demonstrate the fallacy of this. I will compare two theoretical Catholic Diocese on opposite ends of an extremes.

In Diocese A, there is a network of janitors who steal cleaning supplies and sell them on Ebay. About 5% of the janitors are in this network. They assist each other in locating valuable supplies and removing them from church property. The bishop of this diocese is aware of the theft, but does nothing to stop it.

In Diocese B, there is a network of serial killer priests. About 5% of the priests are serial killers. They assist each other in locating victims, killing them and hiding the bodies. The Vatican is aware of the murders, but does nothing to stop it.

Are these two situations morally equivalent? Even though we know each component of each story happens individually, when we put them all together, do both shock the conscience equally? Do both have the same implications for the church as a whole? It's simply absurd to think they do. Yet that's what some argue.