Because they have the attitude of the average Reddit mod thinking that they're the smartest person in the room.
They believe they will be the ones in administrative control, which would allow them to blather on with impunity in an echo chamber, as they don't want someone to tell them their utopian ideas just aren't realistically based or possible because of basic human programming.
Talk to a commie and ask them about the atrocities, elimination of the educated class and enslavement of the working class and they tell you it either didn't happen or it wasn't real communism. As far as I can tell no communism ever practiced by anyone has been "real communism" in their little coconuts.