Because they invite further ideas.
Because they need to be let loose to rub shoulders with other ideas in order to figure out what they really are.
Because they need to stretch their legs and run a round a bit after being stuck in your head for a time.
Because they are pregnant with possibility.
Because they grow and transform as they come out into the light.
Because waiting for an idea to be fully formed or thought through only leads to paralysis.
Because in reality no one likes a know-it-all, but everyone loves a dreamer.