I have to agree with Randal wrt OT posts. IMHO I think the reason PM is successful is because of some of the very things you wish to change. For example, the OT stuff is generally weeded out and the folks who are not serious about Perl in general tend to leave since they don't get fame by posting trash. (See Slashdot for examples of this kind of thing :-)
If something dubious is posted to the front page for example, it can be quickly removed (e.g. voted out of existance). Notice that OT stuff is still allowed -- just discouraged in general unless the "community" thinks it's worthy. If you peruse Slashdot, you have to take the good articles with the bad and you have to surf at a high enough level to avoid all of the trash since a large number of bottom feeders there are quite vocal -- even ones with monikers.
As for Anonymous Monk, I agree that folks should pick a moniker, but not so they are somehow showing backbone, but so that their messages can be attributed to a common source (i.e. If I'm short on time, I focus reading messages from folks with a low SNL ratio.) If they don't want a message to be attributed to them, what do I care -- they could just pick another random moniker and login and post with that.