one shared namespace is problematic for reasons. You can figure email though, right?
DNS is a solved problem and we're never going to see anything better come along because DNS has survived the test of time (see the Lindy Effect - DNS is old, crusty, and like the Art of War or Shakespeare, it's worth learning).
(In passing, using top level domains as user id may be a good idea in some cases. In tech communities the friction may be bearable.)
I assume you aren't familiar with the Lindy effect though and I apologize for making an arcane reference: https://en.wikipedia.org/wiki/Lindy_effect
OK then:
> "that's a feature, not a bug! one shared namespace is problematic for reasons."
Is just saying "I'm right you're wrong and I refuse to explain why".
> "You can figure email though, right?"
Are you saying that being able to understand email means one should find the benefit to separate namespaces in social media? Or that email is everyone's definition of perfect and so everything should be like it? Or something else, considering it took me a bit of guessing to even think of those first two explanations?
> DNS is a solved problem
First, are you suggesting DNS is 100% perfect at what it does and nobody could ever have any complaint about it? Second, it's not clear to me how it being a solved problem for what it currently does means it's necessarily the right approach for any new uses? I need to get a tire on my car replaced tomorrow, and I really hope they don't tell me "you don't need a new tire, you need DNS - haven't you heard, it's a solved problem".
I'm genuinely not trying to be sarcastic I just don't understand any argument you're trying to make.