Actually, speaking as a former leftist and *very* small scale student activist, it’s because they have examples of it ‘working.’ Which they do - see the shockingly collectivist Israeli kibbutz settlements/farms. What they fail to realize is that communism only works in certain very limited circumstances and cannot work as a national system of government.
Communism only works and is not a monstrous abomination if and only if the following conditions are met, as best I can tell from history and personal experience:
1. There is a clear threat that needs to be dealt with or a goal that must be achieved that everyone in the group agrees upon. This is how lifeboats typically operate, or stranded survivors on a desert island work.
2. Literally everyone must agree to the goal and what they are going to do to achieve it. If anyone significantly disagrees with the broad strokes, it won’t work.
3. The maximum number of people that can be subject to this is maybe 1000, often far less. Again, everyone must freely consent and agree with the goals.
4. Once the goal is achieved, either the commune is dissolved or a new goal is agreed on by all participants.
Fail to do any of these and it flies apart.
In any group of 1,000, you will have 250 lazy people who won’t pull their weight no matter what (short of a bullet to the head). Read the history of the Mayflower and Plymouth colony for a good example of the fast transformation of productivity when people are working for their own benefit on their own land.
I lived in Red China for the better part of a year in the mid 70s. The collective is not a pretty sight.
You simply cannot create a “New Man” because it is so antithetical to deeply ingrained human nature.
A simple question is never answered by leftists: “why didn’t the amazing advances in technology, products and services the past 250 years originate in totalitarian regimes”? Even the hilariously stupid CHAZ “garden” provides proof of collective laziness and abuse of those who do the work.