My definition of “capitalism” is:

An economy with capital markets (in addition to markets in goods and services).

Most of my friends and acquaintances generally don’t have a precise definition of “capitalism”, but use the word to mean something like:

The economic status quo.

Before I realized this, these different definitions of “capitalism” led to conversations that were a lot less productive than they could have been. I argued from the pro-capitalist position, relying on an abstract view of economic systems, they argued from an anti-capitalist position, motivated by concerns about concrete problems like economic inequality, and we ended up talking past each other.

Not all socialists are socialist

This semantic underdetermination (or, in simpler terms, vagueness) isn’t just relevant to laypeople. For example, the leftist economist Thomas Piketty advocates a series of reforms, including a steep wealth tax that would prohibit dynastic wealth, that he bundles under the name “participatory socialism”. None of these reforms is to abolish capital markets (or markets in goods and services).

Some political parties, such as France’s Parti socialiste, use the term “socialism” interchangeably with “social democracy”, which is a reformist school of thought that does not call for the abolition of capital markets. Other political parties, like Norway’s Sosialistisk Venstreparti, seem to prevaricate between social democracy and revolutionary socialism or Marxism.

This helps explain why a Pew Research survey found that 44% of Americans aged 18-29 had a positive view of socialism, while only 40% had a positive view of capitalism. Among Democrats in the same age bracket, 58% had a positive view of socialism versus 29% for capitalism. I doubt that Marxism-Leninism is that popular in America. These people more likely have in mind the Nordic model than the Soviet Union. 

The economics of the long-term future

Supposing superhuman AGI is invented this century or, alternatively, radical human brain upgrades become possible, economic growth will presumably accelerate and the productivity and automation of labour will presumably increase dramatically. In this scenario, it’s not clear if the already tenuous “capitalism”/“socialism” distinction will hold. Particularly if policies like universal basic income and universal basic inheritance are enacted, it’s unclear if we will still recognize the gestalt of capitalism or socialism.

If people still care about replacing capital markets with democratic institutions like publicly-owned investment banks or federated workers’ syndicates, then this might become a real possibility in the 21st or 22nd century. In a context of economic abundance, the costs of such an arrangement — particularly to economic growth — due to its inefficiencies could become acceptable. Alternatively, advancements in technology could enable some futuristic form of economic planning that aggregates information about individuals’ fine-grained preferences and desires, much as markets do today. In either case, there could be meritocratic competition between capital allocators within these democratic institutions (or competition between different institutions). Supposing markets in goods and services remain, this would be a form of market socialism. 

Conclusion

Depending on your demographics and the demographics of your social networks — particularly if you and your friends are young, metropolitan, and university-educated, and especially if you're also LGBT — you may know a lot of people who criticize capitalism or who identify as anti-capitalist. Regardless, there are a lot of such people out there on the wider Internet. If you don't want to find common ground with those people, fine, that's up to you. But if you do, there is room for agreement, or maybe just sympathy, or at least less polarization.