Have you been to TDS? It's not quite that simple. And DCA is losing bug's land, so by your metric it will look even worse shortly. You also forgot 20,000 Leagues Under the Sea.
Parks aren't just collections of rides. TDS has something DCA has always lacked - wonder. The lands are layered, with alleyways and places to explore and poke around. Fortress Explorations alone, which is jaw dropping, makes TDS a better park for children than DCA. The playground grotto in Mermaid Lagoon is child heaven (heaven for anyone who likes Mermaid, actually). Then there's the lavish and plentiful entertainment - harbor shows, Big Band Beat, King Triton's Concert, Magic Lamp Theater, Hello New York, Fantasmic, characters everywhere - TDS is a far better family park than DCA has ever been.