Neither. Both are inherently flawed.
I don't particularly recognise a great distinction between humans and robots. Both humans and robots operate according to incentives and their ability to calculate the course of action that lies most in accordance with those incentives. Humans are however individualistic, so an individualistic capitalist economic philosophy appears to work better.
If people are getting their 'communism will never work' views from History lessons, sorry to tell you but we're being taught about communism in an incredibly biased, propaganda-fueled way (we do live in a capitalist society after all).
I don't know enough about it to fully say I'm a communist, but it IS the only ideology that benefits all of us. Just look at Cuba...
Without defined and enforced private property rights our species would be woefully inefficient with much less of an incentive to innovate and compete.
Also, human nature is based around the notion that you are only truly selfless towards those with whom you have an emotional connection with. Without that connection we see time and again that our core nature pushes us to act in our own self interest.
Communism is great in theory. However, in reality it could never work. Why? Because of innate human greed. Communism could never work because individuals (not all, but some) would never be satisfied with working for the benefits of all, they'd always strive for 'a bigger slice of the pie', so to speak.
The same problem (of human greed) is apparent within the capitalist system. Those with the wealth don't want to share it, thus profits aren't circulated equally in the economy, thus increasing the polarisation of different social classes. Perhaps capitalism would work if there was a stable equilibrium (where everyone was starting from the same point), but there isn't. Therefore capitalism only enhances the distance between those with more and those with less.
There is the argument that those at the top benefiting from the capitalist system are those that deserve to be there, and those that don't benefit simply haven't made the most of the opportunities handed to them by capitalism. However, this is merely a façade posed by those at the top to justify the corrupt system that most Western countries work in. In actual fact, capitalism is simply the exploitation of those most needy; profits made by those at the top created off the backs' of workers.
selfishness is an evolutionary trait that all humans have, and it is a natural thing to revolt against anything that could create equality and mean you have slightly less