There are a lot of holes in modern mainstream economic thinking, a large number of which are actually pretty old. We've been having what are fundamentally the same economic debates for 2000+ years, largely over fairness of pricing, wages, equity, and control, as a survey history such as Roger E. Backhouse's The Ordinary Business of Life details.

In the 20th century, the three major challenges to free-market capitalism as espoused by Adam Smith and his followers have been the Great Depression of 1929-1940, the environmental and oil shocks of the 1970s, and the "Great Recession" of 2007 onwards.

The Depression raised the question of whether or not the free market was itself self-correcting, and the answer is generally accepted as a pretty emphatic "no". It wasn't until massive amounts of government-induced spending, partially through the New Deal, but largely as part of World War II and post-war reconstruction efforts (e.g., the Marshall Plan) that the economy really got off the ground again, and even through the 1950s and 1960s, there was concern that the malaise of the 1930s would return.

What happened instead were a series of environmental and safety concerns -- Rachel Carson's Silent Spring, Ralph Nader's Unsafe at Any Speed, and more so the question of whether or not the modern post-Industrial Revolution age was sustainable: the Club of Rome's Limits to Growth.

These were immediately followed by peaking of US domestic oil extraction in 1971, and the first effective middle-east oil embargo from the recently-formed OPEC (several earlier attempts had been made, notably during the Suez crisis of the 1950s, but US domestic extraction could take up the slack). It was also a decade in which the last vestiges of the gold standard were removed from most major world currencies (the Swiss Franc continued through the 2000s), with the cancellation of the Bretton Woods agreement, unilaterally, by the US.

The turbulent 1970s turned into the prosperous 1980s and 1990s, which some attribute to opening up of the North Sea, Alaskan North Slope, and offshore Gulf of Mexico to oil development. Crashing oil prices are thought to have played a major role in the collapse of the former Soviet Union, long dependent on its oil exports for hard currency.

There were also massive political shifts underway. Within the US, the previously white-Democratically-dominated South was split amongst a now black Democratic and white Republic party, while moral and other issues were used to create unity amongst an otherwise increasingly class-divided Republican party elsewhere. Labor unions lost a huge amount of power both due to general decline among US manufacturing companies (particularly automobiles, steel, and other heavy industry), as well as federal action (the 1980s air traffic controllers' strike and dissolving of the union by President Reagan).

While real returns on business investment were falling (look up Deloitte's Center for the Edge study "The Shift Index"), financial wealth creation was increasingly coming from the financial sector itself, and asset inflation of securities and later, real estate (itself driven by securities return demands).

There has been economic growth, mostly in the BRIC nations: Brazil, Russia, India, and China, but most especially in the latter two, with growth in China quite simply blowing away any previous economic revival anywhere, including the post-WWII European and Japanese recoveries. Unfortunately for economics, the growth in India and China has come largely with an almost precise parallel growth in primary energy consumption, a huge portion of that exceptionally dirty coal (in both traditional particulate, smog, and heavy-metal pollution as well as CO2 emissions). Much of the "economic decoupling" of growth from primary resource consumption in the rest of the world disappears if you factor India and China back into the equation.

Then came the 2000s: the dot com collapse, the Bush tax cuts (favoring the wealthy markedly), two unfunded wars, peak oil in 2006, the housing (asset) bubble, 2007 global financial crisis, and growing inequality worldwide.

To put it bluntly, conventional economics predicted little if any of this. The models of the Limits to Growth types appear to be playing out, though with some variance (the post-oil embargo efficiency improvements and reduced oil consumption, as well as fracking and other "enhanced recovery" petroleum extraction methods have pushed back the net fossil hydrocarbon liquids by 5-15 years). The criticisms of Marx, Malthus, Toynbee, and others over the inequality of capitalism have resurfaced with a vengeance. Claims of a "new" economy or "information" economy are proving largely illusory. The Web 2.0 economy is largely funded by advertising, the bulk of which are FIRE (finance, insurance, and real estate) and electronics consumables themselves, as well as exceptionally liberal central bank monetary policy.

And the critics of economics are mainstream: you'll find articles questioning received wisdom in the Financial Times, Economist, Wall Street Journal, New York Times, and elsewhere. Critics include Joseph Stiglitz, Paul Krugman, James Galbraith, Steve Keen, Herman Daly, and a handful of others -- hardly the bulk of the profession, but some key thinkers.

And as others have noted, "anti-capitalist" is at best a label of convenience applied to a system that could be characterized by a great many things. I've called it the economic orthodoxy (as opposed to heterodoxies). Salient characteristics include free markets, laissez-faire (according to some), corporatism, financialization, globalization, commoditization, computerization, automation, extraction, nonsustainability, and others.

All of which tends to be a bit of a mouthful. There's also a fair bit of disagreement among critics on just what the most relevant elements of failure are (as is typically the case -- it's easy to agree that you don't like the old boss, harder to select a new boss you happen to agree on).