It's making things for consumers now, and under current economics there is a motivation to keep consumer numbers high (this is why there are many indications that when a population goes into decline it creates a bit of a crisis for an economy). However, if those who already control resources, including production, no longer need producers, you can have a dramatic shift. For one, the ones at the top already have enough resources to last them a while, but now that they control production of anything else they need, they don't need a consumer economy. They won't make money anymore, but it won't matter, as money is mostly meaningless if you control resources. Once there are less consumers to try and drain in order to keep them working (since you no longer need them working) you can shift production over to whatever the person in control happens to want, and can thrive quite well on smaller production (due to producing for significantly less people) or greater variety, if desired, but lower production becomes a good thing anyway as that means you conserve resources for longer periods of time (your dynasty can last forever). No more worries about human usage outstripping the planets resources, or even that there are too many people to split the gold between for one person to amass enough to build that giant Golden House, there are a lot less people and the people less control resources to an extreme (other than, perhaps, some now smaller group of service people kept around). Also, now you can perhaps have 500,000 acre 'personal' woods to thrive and provide for personally hunting grounds or whatever. With smaller populations, less worry about riots and revolution upsetting the power balance (you might have to worry about other bored and greedy controllers, but they deal with that now anyway).
The point I'm trying to get at is, once at the point where production and gathering is taken care of by something a set group controls, to the point that they can continue to produce and gather whatever they personally need and want, there's no longer a need for other consumers, and production can stop churning out consumer based goods and become personal goods (or whatever is desired to trade with the other controllers). The only motivation to keep people around is for personal satisfaction, because you like having human slaves, or for some other resource purpose (larger gene pool to take mates from? Still don't necessarily need the same size population, and you might decide to get rid of any gene groups you don't personally like too). We aren't at the point where that much is possible yet, it's just a possibility if things continue along the same direction.
Yea, I've heard some similar stories, and there was a great TED talk about simulated happiness saying how it's been found that after a year, people who win the lottery and people who loose the use of their legs are just as happy as the other group.
I wasn't trying to say that loosing a limb would destroy a person and make things hopeless or anything, I was just saying, in general, it probably isn't going to give a particular benefit. You might not be worse off in the happiness spectrum (you might be, might not be), and hell, under some circumstance maybe you will be happier for it, I just doubt it's a typical trend that you'd be better than you were before because of loosing the limb. I could be wrong though.