Our 20 year old son adores Orlando, but has no interest in Disney. He much prefers the SeaWorld parks (as an animal lover) and Universal parks (as a movie buff) to any of the Disney ones.
Once Star Wars Land fully opens at Hollywood Studios, it may be enough to woo him back again. At his stage of life, he's just not looking for princesses or childhood whimsy. The balance of the Disney parks don't offer enough thrill rides to suit his adventurous side, and Mickey Mouse has never been a hero for him. We enjoyed our family Disney-only trip in 2009, but since seeing all the other things that Orlando has to offer, he's definitely never expressed an interest to focus additional vacations around the Disney parks.
He's now been to Orlando a total of 8 times (his first trip to celebrate his 13th birthday, and his most recent in April/May 2016), and Discovery Cove is easily his favourite park of all.