These people don't read about AES and their problems. Of course it's not utopian, thinking longer than 5 seconds will bring you to that conclusion. People still have to work in supermarkets, factories, do heavy labour, do jobs they might not like etc. and it will bring with it some new problems.
Michael Parenti, in his book Blackshirts and Reds, gives an example of work related problems in the Soviet Union. Workers were sometimes discouraged to do their work out of boredom and since employment, food and housing was taken care of by the state, you'd find some of them slacking. Turns out that if you do not have to worry about unemployment, starvation or losing your house, you are less likely to work your ass off for rude customers for example. People would sometims leave their jobs in the middle of the day to go shopping, leaving lots of customers behind at the store. Factoryworkers would work until their quotas were reached and did not go any further, because then they would receive new quotas and have to work harder.
Communism will bring real problems that require real solutions. But I'd rather have to find a solution for boredom than having to find a solution to issues that capitalist ideology brings, like homelessness, food insecurity, unemployment etc.
In no way will communism be an utopian society where no problems exist at all. That's a foolish point of view.