There is a long tradition of the use of pseudonyms — PenNames — in literature, politics, etc. to mask one's RealName. Moreover, personas are part of our everyday lives; we display different personalities to different people or groups of people.
However, the tradition of pen names has both good and bad examples. Hence it is fallacious to appeal to that; the possibility of pseudonyms does not imply their desirability. Moreover, MeatBall is emphatically not a masquerade ball, wherein the use of elaborate personas is significant.
However, this merely implies that pseudonymity itself is neutral. It is likewise fallacious to claim that bad uses (DramaticIdentity, ostentation, trolling, etc.) invalidate pseudonymity itself.
Therefore, at least on this basis, acceptance or rejection of pseudonyms is merely a neutral value judgment.
A most extreme example is NetochkaNezvanova.
Don't do that! At least not here.