Earlier quoted context omitted.
> Can you imagine if I release my Twitter account, after almost a decade of constant cultivation of my other professional profiles (GitHub, GitLab, LinkedIn, etc) and then someone starts posting malicious messages to make my username look bad? Oh no, you'll be just like everyone else under the sun who has to use different names in different places. You aren't special and no-one really cares.
> You aren’t special and no-one really cares. Come on now. If someone uses the same username in multiple places, and another site has a user with the same name, it’s easy to assume they are the same person. If there is a risk of impersonation or confusion with another account, it’s fair to try to protect your reputation by registering an account in that name and not posting, especially if you are well-known in some i…
If you want an easily defended but unique identity, pick something that isn't short-and-simple, and you'll have less competition.