"You don’t need to spend very much time hanging around the comments section (or even many of the posts) at Zero Hedge to discern a strong nihilistic and even anti-capitalist strain to much of the thinking in that community. Independent traders are often men in their 20s and 30s who inherited a substantial sum of money and who for whatever reason don’t have a more attractive opportunity in the regular workforce. They work from home, they tend to have a strong contrarian streak, and they have a lot of time on their hands ... It’s a common misconception that all traders are die-hard capitalists. But in fact many of them are quite the opposite. They still want to make money, of course. But that doesn’t mean they want the stock market to go up."
I think it's a question of whether you're using "capitalist" as a shorthand for "people who profit from the investment of capital" or "people who assert ideologically that an economic system in which market actors trade as freely as possible is the most beneficial system to society as a whole."
The varying reactions to this interview are interesting to me in how they reveal people think about the market. I'm seeing a lot of pushback along the line of "So what? Most of what he says is true!" I think people's negative reaction is a result of a decade or more of an ideological push to get ordinary people's savings into the stock market, and, furthermore, to portray the people who are active drivers in those markets as job-creating heroes who know better than some government bureaucrat and who therefore deserve their high compensation. When it's revealed that at least one such marketeer dreams of profiting from a general economic collapse, that seems to invalidate the promises of an ideology that is often described in shorthand as "pro-market" or "pro-capitalism".
Capitalism is about the allocation of capital, shorting a stock helps alert the market to the possibility that the stock is a poor place to put your capital.
Profiting from a market collapse is the preservation of capital which is exactly what capitalism is supposed to do. This kind of profiting would be disallowed by a less free market system and thus the populace would suffer a worse fate as more capital is destroyed via mismanagement.
Capitalism is not the idea that stocks and other investments go upwards infinitely. Capitalism is about the idea that we live a better life when capital is allocated efficiently. It's a good thing that we don't allocate very much capital to buggy whip manufacture. Allocation of capital to those concerns would beget the production of goods we don't need.
Similarly, the market is allocating capital away from national governments who wastefully spend it and allocating it to governments who can put the capital to good use and return a profit from the proper stewardship of their capital.
At first I also assumed the same. However, if it's a hoax it's a pretty elaborate one. He appears to have an online presence as a trader going back at least to 2009.
My guess is that he's just making outrageous statements so that he can get on other news and chat shows.