We keep the moderation light because otherwise it's a damn nuisance.
A "damn nuisance" to whom?
The moderators.
People get put on mod by being massive pains in the backside. Even then, their messages get through if they aren't a continuation of being the massive pain in the backside.
A "pain in the backside" to whom?
To the readers of the mailing list. It's usually fairly obvious from the replies when people are getting annoyed.
people posting annoying rubbish
"annoying rubbish" to whom"
The readers of the list - see above.