To be honest I fail to see what these good reasons are.

Just change the registrar and the problem is solved. Give some transition period during which renewal fees are not subject to change.

.su domain seems to exist just fine. As for:

"But ambiguity is the worst thing for a top-level domain. Unknowingly, this decision created an environment in which .su became a digital wild west. Today, it is a barely policed top-level domain, a plausibly deniable home for Russian dark ops and a place where supremacist content and cyber-crime have found cover."

...it feels like a bunch of FUD for me. The registrar is known. The domain is official. What exactly makes it more "wild west" than, say, .ru, .rs or .xyz?