Existence does not equate allowance. Have you reported their profile?
Their user name is their user ID. I assume it has been handled now? What's your take on that after these public accusations and it supposedly being the reason to make your own spaces?
I report stuff when I come across it. I regularly get info on action being taken.
It's a community platform. Individual, manual username change assessment and approval is infeasible. What's your expectation?