In simple terms, capitalist farmers produce a surplus, kibbutz farmers produce a deficit. Kibbutzen operate within a market economy and have all the resources of it that are available to the capitalist farmer - they still can't make a go of it.
> not a principle of communism.
Collective ownership of the means of production means confiscating it.
> Forced labor
When the collective decides that certain work must be done, and with no market forces, that means assigning people to the jobs. I.e. forced labor.
If you wanted to say that there are major fundamental problems with having no markets, I'd agree completely. Communism is not a set of ideas necessarily anti-market.
https://en.wikipedia.org/wiki/Market_socialism
Or, to be pragmatic, if we agreed for this exchange that "communism" meant precisely an economic structure without markets, then I'd agree that's simply unworkable. All of my points in this thread rely on my assumption that the term "communism" refers to a wider scope of ideas and models, some of which have some merit but which nobody ever should dogmatically advocate (nor should they dogmatically reject as being synonymous with Lenin/Stalin/Mao).
"having all their property expropriated and being forced to work on collectives" is also not a principle of communism. Forced labor is not a communist value.