The problem with capitalism is that you eventually run out of things and people to exploit.
I'm not a socialist, just demonstrating how dumb Thatcher's statement sounds. No system is perfect on its own, pure socialism doesn't work but neither does pure capitalism.
In capitalism, you earn money by creating value that others are willing to exchange money for. A farmer sells feed for more than his cost of producing it, the hog farmer buys feed and raises hogs on it, then sells his grown hogs to a butcher at a profit. The butcher sells bacon and sausage to people who don't want to raise grain and hogs, but are willing to exchange the money they earn from being a mechanic or writing software for the food they eat. The government doesn't set the prices they must charge or pay, but things self-regulate so we get more of what people are willing to pay more for, which draws more people into that field so,prices come down. We have odd situations where sports stars get millions of dollars, but team owners and advertisers believe they're worth that much or they wouldn't pay that kind of money. People choose the kinds of jobs they do based on a combination of ability, monetary compensation, satisfaction and phychic rewards.
I'm not a socialist, just demonstrating how dumb Thatcher's statement sounds. No system is perfect on its own, pure socialism doesn't work but neither does pure capitalism.