Player inertia. It probably applies to campaigns other than mine, too. They like to think they're playing "D&D" (and the spells make it seem the same) - but it hasn't been, for years...
Plus, now we will hopefully have a new influx of ex-D&D-ers, disenchanted by 4e. Using spells they're familiar with should make their transition so much easier.
And the spells need hardly any translating for this system (and perhaps peterb's too). Define a few straightforward principles (e.g.: "AC" becomes 10-x APs; "+X to hit" becomes +X0% attack; any more?) and it could be done on-the-fly. (The difficult part is resisting the temptation to change them for the better...!)
__________________
280/420
|