If someone opts to use AFCIs in lieu of rewiring an old K&T or ragwire house, and a resulting possible series arc causes a blaze that kills the occupant(s), then yes, I would have to say that they are a bad thing and have the potential to hurt someone by not doing what the name suggests that they do.
When they start putting "Surgeon General's Warnings" on them spelling out to Joe Public that they won't detect the very scenario that is most likely to cause a fire (loose terminals, splices, connections), then I'll be for 'em.
In the mean time, I'll keep installing them.
[This message has been edited by sparky66wv (edited 01-25-2003).]