Bright sparkling loose ideas are always more interesting than those that have been carefully mortared into place in a complete story arc. Of course then you have to hammer your head against the wall trying to mortar them in and figure out how on earth the hero is going to manage to get from point A to point X in order to get both ideas in.
But what is perhaps the real charm is that outlining is quick. You need a lot less detail for "Jane searched the room and found the ring" in an outline, where that suffices, than in a story. (Mostly. If Jane had found nothing, the scene might not be needed, but most of that gets omitted in both places.)
sigh. There are so many writing related ways to avoid writing. (At least it's not a temptation all the time. Depends on the mood.)