Tags are much more noticeable than user names. It tends to stick out more from the rest of the post and makes you notice who the poster is. After seeing them enough you tend to get a feel for the type of content they post about.
You can put your own nickname next to the names of other users, to catalog them/ mark trolls or whatever. That seems to be what Don is doing inbetween Rampages
Yeah, there's a lot of power posters here. PugJesus is an example from the opposite camp, calling out the anti-Democrat propaganda from the two OP mentioned.