I know that the list admins have been criticized of late for letting through messages that people have questioned. However, this list is the forum of last resort for people who have been banned from post to Wikipedia.
It rarely does any good, though. It would be better if they emailed the admin in question, or ArbCom.
I'm one of those who see very little harm in letting through a hostile message. No one is forced to read the message.
There is no way to know if you want to read a message before you've read it, so you are forcing people to either read the message or not read the list at all. (You could read all the messages that don't mention admin abuse in the subject line, I suppose, but that would still result in you not reading perfectly good messages about admin abuse.)