Fantail launch, etc What's the point in a Fantail?

I like the looks of the Fantail, and it looks like a good place to stand and fish from.
It's on boats up to 90' or so.
What's the original intent or reason for the fantail design?

 

Originaly a sailing ship feature, stronger structurally, protected the rudder, and added buoyancy aft on the 'cods head and mackrel tail' or clipper waterplanes of the period, however some of the later ones, like some on launches, were stylized to extremes just for the deck area. They ended up being so common that "fantail" is now the name for the aftermost part of the main deck.

 

I think the Deck space is what caught my eye. Maybe the rounded surface under the fantail might make it a bit tippy or rolly if the boat was in the 22 to 24' length.
I'd want that deck right down on the water for easier fishing. So what if you get your feet wet?
I'd also want the engine up in the center of the boat. At least forward of the last 10 feet of the boat. So the fantail was a nice roomy 8' by 10' space, down low on the water and fairly level.

 

Unless the water you fish is very, very flat, an extreme fantail is a poor choice. It would be nosiy, uncomfortable, and jerky. The reason for the shape of the overhang and lack of transom was to cause the stern to lift to the waves. A long, low overhang would cause too much waterplane change which would drive motions, as well as having constant slap from any chop and allowing stern wave impingement.

Edit: what you may want to look at is a draketail stern. The cockpit sole would be just at the waterline and the knuckle would just kiss the water.