Although they both kind of reflect the same underlying selfish attitude, IMO, the chair hogging is a much greater issue than kids in the adult areas. First, because I believe it much more prevelant, and secondly, because of the design blunder having the elevator dump you out in the Quiet cove area on the Dream/Fantasy.
When we were on the Fantasy last month, I was up earlier than the rest of my family and went up to pool deck to get a coffee from the beverage station. It was about 7:15am. There were maybe only a dozen other people around. However, I noticed at least 90% of the chairs around the pool already had towels and/or other stuff on them. It's so ridiculous. I also later noticed (on all 3 sea days at least), that the same family had the same exact handful of chairs each day - first row right alongside the Donald pool. Not a coincidence, as no way that's possible unless one of them are going up there at the crack of dawn and throwing some stuff down on the chairs...then going back to their room, having breakfast, etc. And it's clear many, many families do this. Purely disgusting behavior, if you asked me. And I've seen it at WDW resorts, local hotels/resorts, other cruise lines, etc. Unfortunately, until the hospitality industrty comes up with an effective solution for it (a very difficult task, I acknowledge), it will continue to be a huge problem.
Wow, that's insane. That is when their stuff definitely needs to be moved. I can't believe people will actually do that. Society has taken such a downward shift in this last decade.