For the record:
killergotrekt saw the glorious days of minehut, in which this rule did not exist.
Back in our days we could grief all servers and get away with it, until they added the community disruption rule which keep in mind was not even in the rules list back then and it was a pretty lame excuse to ban some blacklisted people.
I fought against that "rule" back then
Some time after minehut decided to make the "no grief rule" a thing since community disruption's "rule" was most of the time used against player server griefers.
Now I do get it that this is an attempt to reduce the amount of complaints from players because of servers getting griefed.
The real question here is: Should there be a rule against player server griefing? And the answer is simple: Minehut does whatever it wants lol. Its their server so they get to choose what the rules are.
My theory about why we are even discussing this is because this was not a rule for a long time back in the old days, and people were used to it not being a rule. The fact that killergotrekt started this discussion shows me that I might be right, because he was one of those players.
If you want my opinion: I am against the rule, cuz its funny to grief servers.