They include stats as class/abilities limitations. It's a different set of stats, but they are stats nonetheless. However, my personal opinion is that by having rules vary from one RPG to another may get messed up over time, so that's why I, for one, would encourgae a Core Rules system. Even if some RPGs chose to ignore them in the future - and they'd be free to do so - GM's could follow it to have one less thing to worry about, and also to have a standard. But the RP Forum is not that active anymore, so I think it doesn't matter. Otoh, it could shake things up and bring people back to rp'ing.