Communism works with computers because it costs almost nothing to copy a program.
Communism does not work with these products:
>school resources like books and buildings and teachers
>other consumer goods
The reason it does not work with these goods is because these are not so easily copied. It costs immense resources to produce many of these, and they are not finite. Land for example is very finite, and there is only so much to go around.
Housing is very expensive, because land is finite, and the labor and materials to produce housing are expensive.
The expensive nature of housing drives up the prices for things like food and books.
Communism is perfectly fine for a vast swath of programs because programs can be made free.
Food and clothing and shelter for example can not, therefore outside of computers communism is not viable.
It is perfectly valid for someone who is a republican in real life to be communist within a computer.
It is invalid for a computer communist to think that this infinite abundance for no work is possible in real life outside of a computer.