Although I've been a bare fingerstyle player for more than a few years now, my recent purchases of a 12 string and a resonator (and plans to get a 5-string) make me see the need of something to make me less prone to shredding my fingernails.
With traditional finger picks such as Dunlop and National the playing edge sits under the finger, over the meat of the fingertip, far away from the fingernail's edge, completely changing your angle of attack, as do the thumb picks. Great for flailing not so much for delicate or complex lines.
There are number of designs that attempt to move the fingerpick's point of attack closer to the position of the nail itself.
Perhaps these styles of picks should be called FingerStyle Picks, instead of FingerPicks?