There are two scenarios where a locking folder is more valuable to me than a slipjoint.
The first is for stabbing, which has almost nothing to do with EDC. It's why I carry a large, locking, OHO for self protection if going into a "less safe" situation.
The second is when the need might arise to loan my knife to someone else. Lockers are both safer for the unfamiliar users, and easier to open. I don't care if they know how to close it, they can just hand it back to me when finished using it. This is why I always carry a locking traditional when opening Christmas or birthday presents.
But in addition to need, there is desire. I often carry a locking traditional just because I have several that I really like.
"It's no use growing older if you only learn new ways of misbehaving yourself." H. H. Munro