I can't have an opinion on that. I don't have any experience with it. But, I'm sure each case is different. Some adult children do become freeloaders mostly because their parents enable it. My first husband went to live with his mom when we split up. She cooked and cleaned and washed his clothes and waited on him hand and foot. She LIKED having her baby boy at home. Win-win for those two. When she died he went to live with his sister and she did those things for him.
Other adult kids are really trying to make it and need to save money. My sister's 36-year-old son lives in their basement. I stay out of it. My kids knew if they wanted to live back at home they'd be paying, cleaning, doing chores, and maybe even waiting on me!! I think they avoided it at all costs!