Just like adding comments to moves in a pgn file only when you view the game on RHP you see the comments. Could also have it where you can add the moves to the game. Like if you wanted to add comments to a GM game that would be useful to the viewer.
Judging by the page displays and the featureless forums I would guess that the site owners main objective is simplicity and fast page loads. I agree however that your suggestion would be a nice feature.
If you are interested in displaying your own annotated games on the web I have a few suggestions. You could find a decent free webhost or a reasonably priced (1and1.com is cheap) paid host and put up your annotated games. I have used the following for page generation and they both work well:
Just noticed that the 1and1 'home' package has 10 ftp accounts at $5 a month. If you could get nine other people interested thats six bucks a year per.