All boats were originally loose rigged, and the toggle under the bow would balance the jib halyard and forestay.
A tighter rig is generally better in higher winds, so I would imagine that tight rig came about to make the boat more manageable in coastal winds.
Tight rig is a job to set up, and likely puts more strain on the boat and standing rigging. Snug has enough tension to keep the rig from flopping around, and can be tweaked up or down to suit the wind.
It seems like a pretty good compromise, and most new sails are sold for the snug setup.