I think sailing tech has something to do with it too. We just upgraded from a 1980 C&C 24 to a 2001 Catalina 310.
The C&C was a "simple" boat that had a hank on jib (changed that after a couple of years) and no traveler, just a main sheet in the middle of the cockpit. The engine was a 4 stroke, 6 hp outboard and tiller steering.
The Catalina has a roller furler, traveler, all lines lead to **** pit and a dutchman system. The engine is an inboard diesel and wheel steering. It also has items like a windless, full head, etc.
We are still getting to know the new boat (only had in the water one weekend so far) but it already seems easier to sail and maneuver then the C&C. (once I figure out the crab walk thing) So in the past people may have bought the smaller boat to learn on and then upgraded. Now it seems like you can just jump to that 30+ boat without needing to learn on the smaller boat.
I do also feel that the American consumer aspect pointed out by others is part of the reason. How many of us are just baffled by the beautiful boats sitting at the dock day after day while we go out sailing in our cheaper boats? It seems like many people just own boats are part of status symbol and not to get out and sail.
We spent virtually every weekend last year on the boat from Friday night to Sunday night. This year we plan to spend from Thursday night to Monday morning. And next year I am hoping to convince the wife to live on the boat all summer. So having items like pressurized water, a micro wave, etc. made sense to us. The TV came with the boat and the only reason we have not removed it yet is because we plan to use it to check the weather.
As I mentioned, we do a lot of sailing with just the two of us and the dog, so the autohelm was more of a safety item to us. As was the radar. I know people have sailed for years without these items but why not increase your safety with them?
The wind instruments were just a plus and I would likely not have installed them if they didn't come with the boat. I didn't even have a wind indicator on the C&C. Same with the windless. But they are nice to have as extras.
“Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.” -Mark Twain