"The more they feel that the system is rigged against them, the more they will demand the system itself be overthrown"

The author talks about it like the only alternative is overthrowing the system. This is another extreme, maybe the word you should use here is the social market economy (https://en.wikipedia.org/wiki/Social_market_economy). We use this term here in Germany, even our most deregulation friendly party is committed to it and by definition it's still capitalist.