I've often wondered the same thing. Yeah, there's some rich folks out there, but I always figured that if you hit a certain money point, you were doing things other than cruising. (Or if you were, you were going on one of the "rich" cruiselines that have smaller, fancier boats where everybody gets a butler.)
Anyway, don't worry about what everyone else is doing. Spend on the kind of room you're willing to spend on, and don't worry about being the frugal person. There's a lot of variety if you know where to look. Research the boat you want to go on, see what kinds of rooms are available. You can often find a good surprise.
I don't even go for balconies most of the time. I try to look for the bigger oceanview rooms. The last one was nice because it had portholes with a view of the bow and you could see where you were going, and there was a kid-sized bunkbed area for the kid to have all to himself. (I think Icon is adding a lot of these types of rooms, IIRC...)
Now here's one I don't get... How is it all of you have old folks that aren't afraid of boats? I'd love to take my mom or mother-in-law on one of these things... The issue is getting one of them on one!