Is "both-sides-ism" just the grownup version of group punishment in school?

When journalists and others report on public and especially political misbehavior among adults (such as at a debate), they often cloak their criticism of one party behind a generalized rebuke of both: “Both sides could have shown more restraint,” etc.

Kids in school encounter a version of the same thing: one kid shoves another, and they both go to the principal’s office.

How many will get reprimanded, one or two? How many will get detention? How many will get suspended?

Kids at a lunch table are told that if they don’t quiet down they will have to pick up trash during recess. One kid quiets down and the rest continue to be rowdy. They all get sent to pick up trash. The quiet kid learns that he can’t escape punishment even when he obeys.

Aren’t these all instances of cowardice on the part of whoever is calling out the bad behavior? Whether levying punishment or just exposing the offense, aren’t they being too cowardly to name the actual offender(s) and instead laying blame on everyone so they don’t have to take responsibility for their own actions?

What kind of model is it for kids to be taught that the facts don’t matter, that authorities are arbitrary and capricious, that what they do doesn’t affect what happens to them, and that those who wield the hammers are just as afraid of the bullies and troublemakers as they are?