Since as Marx shows this is not really in the interest of the upper classes (that is: tyranny and extreme poverty are precisely what leads to a violent reaction by the down-trodden) it may be thatIt's not just about violent reactions; simply because extreme poverty does not benefit the very rich in economic terms... in fact, it harms them. And some (maybe a few, maybe most, who knows?) of the very rich understand this; look at what Larry Page and Sergey Brin did in establishing Google's charitable foundation. They understood that - in the end - their ability to grow their business requires a population of healthy, productive, engaged people to do Google searches.
it may be that, through the miracle of technology's abundance, we will continue on a track where we all have a high quality of life, but only a smaller and smaller pool of people "own" the production engines.
If anything, technology seems to be making it easier and easier for people with less capital to produce things. In "our world" (that is, computers, software, web-based consumer sites, etc.) it's already possible to build a software startup with a negligible amount of money. Open Source Software and cheap hosting from Linode, Slicehost, etc. have made this stuff way accessible.
And even in the world of physical goods, every time we turn around we're hearing more about cheap 3d printers that make it possible to spit out real world physical items without a big, expensive factory.
Print-on-demand books make it possible to become an author / publisher for almost no cost. And the "print on demand" concept has been applied to other areas... have artistic talent? You can quickly be in the business of selling your art via the Internet, as clothes, prints, etc.
Now granted, doing something like making jet engines or automobiles still takes a lot of up-front capital, but still... I think the trend is towards more and more forms of production becoming more and more accessible to everyone.