If it made strong sense to live with my mother, rather than on my own, then I'd have done so. How it's perceived by others is irrelevant to me. That said, I can't think when I'm not living by myself and I have difficulties getting along with my mother, so this would've never been an option for me. It's bad enough that I'd be better off alone in a high crime, run down, low cost area than with others in an upper class neighborhood.
If many are still living with their parents, then it implies the recession of 2009 is still inflicting damage, but what's annoying me is the notion that what was previously smart, frugal, and sensible gets baked in as the norm (creating more misery for everyone, but without any advantages). That is, living with parents after graduation is done to just survive, rather than to save more and pay off student loans faster. What BS!