As I observe that this thread is dominated by the bobby-sox school of history and political philosophy, and I don't want to honour any iof them with commenting directly on their posts, I will just answer you.
The point is; it is not about how great capitalism is doing.
It is about how great people are doing. All people, not only the privileged ones.
And then it is a moot question how great capitalism really has been doing. I for one, am not impressed. Unless we talk about its criminal record, which admittedly is unsurpassed, that is...
Some things I have wasted enough time on to bother to elaborate on here.
Like the fact that todays "libertarians", disregarding how little l' they write it with, has no right to claim to be the heirs of the classical liberals.
Like the fact that various shortcomings of the contemporary USA has been pointed out a multitude of times, including that its great social mobility is a myth.
Like the fact that the so-called true or pure capitalism is a pipe-dream, as capitalism being an exploitative and hierarchic system will need some enforcing establishments, and would never exist without a state.
Because when we talk about capitalism, we mean a social system. There is for instance no particulary political system that need to accompany it, it can do well both under limited democracy and dictatorships. As the example of Chile demonstrates, a dictatorship seems to be the best for the more extreme version. Actually, one could be tempted to say that capitalism really is the continuation of feudalism with other means, admittedly there are some differences, but the similarities spring more to the eye.
Finally, the shortcoming of capitalism is not only its economical and social injustice, but also the fact that it is a moronizing system. Or perhaps infantilizing is a better word. I can understand that some of the Usual Suspects on this board are horrified to live in a commune, because that would involve having to take responsibility as a free adult, not living the whole life as a giant baby indulging in commodity fetishism, tittytainment and the observation of their own belly-button. The ancient Greeks, who in some ways were more mature than we are, had a word for such people. They called them idiots.