Remember, Disney is different from other cruises in that it's programs, and the passengers it attracts tend to be early to bed early to rise folks. We had a great time, but noticed a profound difference from our cruises on other lines. Most ships just start hopping about 11 pm, Disney starts winding up about 10pm, and except for a few nightowls, it's pretty quiet from 11 pm on.
We have always had late seating, and having late seating shows BEFORE dinner really threw us for a loop. Again, the early to rise , early to bed theme, most cruises don't have the late show until 10:30pm, and often that is the most packed show because many Early Seating folks come to see the show a second time, or opted to do something else at 8:30, and wait for the late show.
My kids were 12 and 16 on Disney, and 11 and 15 on our cruise to Alaska on HAL's Amsterdam. We never felt uncomfortable letting them wander around alone at night, but I admit it was rare because we did just about everything together. The cruises for us are FAMILY vacations, a rare time when we can eat all our meals together, and let my wife and I be our kids friends for a week, not mom and dad.