Living at home at 30 represents a failure of one thing: career.
The reason most* live at home is money, right? As much as Miles wants to run around in circles about irrelevant shit, it comes down to people living at home because of money. If everyone in this thread living at home made $200k, would they live at home?
*Now there are cultural and personal reasons too, no one denies that. But let's take the most vanilla case that keeps getting thrown around here: need to live at home to save money.
If you need to live at home to save money, you fucked up. Before you ever leave college you should have secured a position to begin upon graduation. This is what internships, career centers, recruiting fairs, open houses, etc. exist for. There should never be a reason to go home because you need to look for a job. That is laughable. That means you did fuck all in college.
If you did secure a position and still need to live at home, that means you picked a career that doesn't make enough money for your area's basic lifestyle. If you live in NYC you know how much you have to make and which careers give you that option. If you chose to be a librarian making $20k, then you living at home is a result of you making poor choices. Not rising rent or the economy lol. If you live in Kansas and chose to be a librarian making $20k, you're absolutely normal because you knew that would be fine to support a life there. If you're working and living at home, you either fucked up your studies or didn't find the job that you need to make your career thrive.
If I meet a 30 year old living at home, the first thing I'd think is sick family member or their culture. Any other reason can only mean one thing: they fucked up. And that's why it's judged, not because I think they're immature or afraid of failure or play games all day. It just means they lost at the easy game of life.