I know of a guy who used to run charters on a tall sailing ship. He had a successful business for years. One day he sold his share and got out of the business. Now he's a canoe guide for wilderness trips. His main reason for changing careers was the difference in equipment maintenance. Keeping a large sailing vessel going requires a lot of work. Modern canoes are pretty much indestructible.
He's an extreme case, but I get where he's coming from. There's a crossover point where the comforts of a boat aren't worth the effort. If you have nearly unlimited wealth, stop reading here. No doubt you have people to do the dirty jobs. For the rest of us, you've got to do a hard nosed cost/benefit analysis.
I'm always looking for the next boat. However, I'm looking for the smallest and simplest boat that will do the job. There are a lot of sailing videos out there so it's easy to see what sailors have to deal with. For many, sailing really is boat repair in exotic locations.
Let's start at the nastiest side of things: the marine head. Always be suspicious of a toilet that has a part known as a “joker valve.” Believe me, the jokes on you when it fails. Holding tanks are nasty. Pumps fail. Over time the waste hoses develop pin hole leaks and your boat develops a permanent funky smell.
Personally, I'd rather deal with a composting head. They are simpler with much less to go wrong. However, there is a learning curve. Cleaning them can be less than fun, but I put on my disposable gloves and get the job done. I've seen pump outs of regular marine heads go terribly wrong and spew black water all over the docks. Believe me, you'd much rather empty out a composting head than clean that mess up.
Things get complicated quickly the larger the boat. Air conditioning, refrigeration, water makers, extensive electronic systems, electrical systems, power winches, massive engines, generators -the list is endless. You can go sailing without any of those things. You've got to ask yourself if those systems are worth it. A person with a small simple boat goes sailing all the time. Big expensive boats are often out of the water waiting for parts and work to be done.
Some people go so far as to sail without an engine at all. While that's pretty simple, it's a bit too simple for me. That doesn't mean you need a huge motor capable of motoring across oceans. Having a small motor that can get you in and out of harbors is pretty useful. If your boat is small enough to use an outboard, it's easy enough to unbolt it and take to a shop, or to completely replace it. Sure beats waiting for a specialized mechanic to fly in with parts.
Of course, it all depends what you plan on doing with your boat. If you will spend all your time tied up to a marina, it's easy to turn it into a floating condo. If, on the other hand, you want to sail and travel, simpler is probably better.
I've used boats as an example, but there are a lot of things that can be approached with the same mindset: cars, houses, computers -anything that can get more complicated than it needs to be to get the job done.
-Sixbears