I don't think the distinction is between old and new. Famously marx was a neet living off a rich man's donations.
There are a certain people who literally are the ideal communist worker in their heart. I've met a couple. They are literally the horse from animal farm. They are hard workers who genuinely put their heart in what they do to do it well, they have no desire for wealth. They make the mistake of thinking most of the population can be like them.
One is a contractor who I've hired multiple times. He is a one man show, he does entire kitchens and bathrooms alone over the course of a month. Impeccable attention to detail and does everything right. And he charges a pretty modest amount for it. He has no desire to grow his business, or to hire anyone under him. He's getting old just wants to buy some farm land and retire on a small farm.
The other is literally from an ex Soviet bloc country and sings the praises of the days when it was communist (before he was born). Also no desire to grow rich and puts his all in his job even though it was a manual labor gig unrelated to his education. Also would imagine himself perfectly happy with a small farm and a bunch of chickens.
They are communists because communism would work if people were like them. But people aren't. Especially not in the west.