Reasons for remaining at home with parents can vary, which is why I usually withhold judgment about people who are living at home, until I hear that they're acting like the assholes in the stories in the first post of this thread. I'll add that my husband is from a country where multi-generational households are the norm due to the high cost of living not being matched by the normal salary that can be obtained by people in their 20's or early 30's.
My husband found living at home annoying, but he was able to go to college, work, and save up. It wasn't an extended adolescence for him, and isn't for a lot of Russian young adults. It's just piss-poor wages for young people that don't match up with being able to pay rent on a shitty, efficiency apartment in a bad neighborhood where your commute to work would take forever, not to mention that after rent there would be fuck-all left to pay utilities or buy food. And forget about putting anything away in savings! The norm there is for employers to just pay a flat monthly salary, regardless of amount of hours worked, so in most jobs it's not like you can pick up extra hours to make more money. It's not a win-win.
I have it on good authority that young Russians want to leave the nest, but it's damn near impossible for a lot of people, even young professionals. It's beginning to be like that even here. I just happened to leave my parents' house when rents weren't astronomical like they are now, so splitting with a roommate made sharing a nice, big, 2-bedroom apartment very affordable to two college students who could still swing working about 25-30 hours a week.
I was able to move out at 20, but my house-sharing situations were never nice until March of this year when my husband and I moved in together. For me, living with roommates, as well as my douchelord of an ex-boyfriend, was awful. There were times it could be fun, but for the most part it was stressful and a pain in the ass. On one hand, I'm grateful that I learned a lot from it and have my independence, but on the other hand, I don't blame others for avoiding it. I wouldn't say that it necessarily made my life "better" to get out on my own when I did. My parents would have expected me to be independent and productive if I had chosen to stay home into my 20's. I would have paid for some household expenses and groceries and cleaned the house, because I didn't feel like living at home meant continuing to be a child. I would've been able to save more money and wouldn't have faced the financial problems I had from 2005 until last year (my ex was a huge, financial drain and I, like a fool, felt obligated to pick up the slack instead of kicking him out or holding him accountable - ya live and ya learn!). All in all, I'm still glad I moved out, since I don't think it's productive to live your life in regret, so I try to regret nothing. It helped shape me, I suppose, to have the experiences I had.
The douche-farts in these stories aren't the same as people who choose to continue living at home for valid reasons.