Yeah, I can think of three just off the top of my head, that live close by.

• One boy, 18 years old. He's been living at home since graduating from high school, some mild nagging to look for a job, but in any case no real pressure, the parents give lots of resources, to the point of funding all kinds of special meals, nice clothes, etc.
• His 21 year old brother is similar, but the parents have actually been funding an apartment for him. He hasn't been to college nor had a job, ever. I think for the past couple years he's supposedly been working with some friends on a video game, and that enterprise fell apart recently. A girlfriend that (according to the mom) was attracted to him because his parents were funding everything, just left him.
• Another young man, probably 22, graduated from a fairly highly ranked college. He's been living at home for 8 months now, no job, doesn't seem to be looking. I think his degree was in chemistry. Anyway, his degree seemed like it something that was reasonable in terms of job prospects, not underwater basket weaving or anything like that.

I think a part of it is that some parents don't have much of a social life. And so if the kids are halfway pleasant to be around, they don't necessarily push them to go live on their own.