Also, should we perhaps count the people who didn't manage to live to be over 65 in this percentage calculation of "20%"? That'll move that number down quite a bit, I am afraid.
> The rich people today were more often than not the poor and middle class of yesterday.
Well, poor people today are more often than not were the poor and middle class of yesterday too.
And yeah, the common populace did object to the higher-ranking party members and bureaucrats having those privileges. One of the slogans of perestroika was "away with privileges", I kid you not -- people would rather elites be as poor as them. Well, the irony is palpable: thirty years later, the common populace is not much richer than it used to be (teachers used to be able to easily travel by plane on their wage, not anymore), but the top-level government officials are way, way better off than they used to be.
And it's because you can always come to the line personnel and tell them: "Don't you just hate it that while you do most of the actual work, the upper-ups earn hundreds times as much as you? Well, here's a solution: ..." And this solution was socialism and trade-unionism in the XIX century, communism in the XX, heck, even capitalism was sold as one in the very late Soviet Union, no kidding — it was seriously argued in the media that privately-owned firms would pay workers better than the state-owned enterprises, just look at the West, and many people actually belived that, really.
Of course, none of those solution ever worked, and that's exactly why they will always be proposed, in one shape or another — socialism itself didn't appear out of nothing, "when Adam delved and Eve span, who was then the gentleman?" was uttered in 1381. So there you go: the spectre of communism will haunt us all as long as inequality exists, that is, until the humanity stops existing.
What country are you describing, pal? In Soviet Union it was "вольнодумство" ("freethinking"), which was a bad thing, to own personal cars / dachas by the highest members of partocracy only. Because that raised questions concerning their loyalty and belief in the system. But even they bought all that under the name of their wives and children. We've got plenty of memoirs of their scions to stop perpetuating the lies.
a) it's impossible for everyone to be a (successful) businessman: somebody has to be an employee and do the actual work, y'know?
b) to be "actually rich" -- which is not just "being on the level of personally comfortable standard of living", it's more of "having certain level of personal influence" -- you have to own a share in a commercial enterprise and get the dividends from it; rare exceptions like a prominent lawyer or a genius surgeon notwithstanding.
These two are mostly empirical observations, and you can frame it very differently depending on your liking; the "exploitation of the worker class" is only one such frame, there are many other.