I think the problem in comparing communism or any other organization vs the free market as reduced to mere utopianism is that this misses the economic aspect. There is certainly a deontological angle to Free Market arguments as opposed to a completely consequentialist approach in any other case I can think of. Respective theorists imagine the sort of place they would like to live in (live in = rule) and then set about explaining how it would work if people just agreed to play by those rules.
The Free Market theorist goes one step further, and also begins earlier, by describing economic law, and then based on these laws, what consequences various actions will lead to. This is part of the reason for the qualifier on statements about what economic policies "work". It completely depends on what your aims are as to whether or not they will "work". The normative part of Free Market Political Economy is the assertion that if you want a society or civilization with peace, with freedom, and with prosperity, you must have a Free Market. Many other Utopias do not claim to provide all of those 3, and in that case there really is no argument other than whether or not
not having those 3 things together is desirable. (For example, Plato's Republic doesn't even pretend to offer freedom from any accepted perspective).
The argument against the Free Market as an ontological absolute is different than the argument against an economic organization approaching socialism or communism. The argument against the Free Market says people won't stop using coercion (there is a counter to this but let's assume that the argument is foolproof). So, it's an argument from human fallibility, or human nature. Conversely, while there is a human nature argument against socialism and communism, the point of the Free Market critique is that
even if human nature were no issue, socialism and communism would both fail due to
economic law. Mises laid this argument out pretty thoroughly here:
Economic Calculation In The Socialist Commonwealth
Regarding suffering, I know we've been over that ground. I will easily and readily concede that even in a theoretical "true" Free Market (and even ruling out exceptions of random evil, natural disasters, etc), there will be poverty, human suffering, etc in cases, and that in the sense that the Free Market makes it possible, we might call a system responsible. But the response to this is twofold: The very mechanism whereby one put themselves into the negative position also offers the way out. Two: The greater prosperity and lack of bureaucracy to pass responsibility off to(with their conflicts of interest and inefficiencies) would more likely provide a greater voluntary "safety net".