I never said anything about using names as a primary key. Of course, you could expand the schema to handle aliases, but in the end, people have names that they prefer. You are kbenson, and if you were able to change your username, the proper action is to change the username on all of your comments.
Think of it as a database. A table of events with foreign key references to a table of people. Now if someone's name changes, you only need to update a single entry, eliminating both redundancy and inconsistency in our database. If I look up events about Beyoncé Giselle Knowles-Carter, I sure hope that I find things like when she was born! If you insist on tying events to name at the time of the event, you have a much greater propensity for losing information whenever anyone changes their name for any reason! Therefore, from a data integrity standpoint, I think every database engineer would prefer the one name for all history approach. You could even store the name change event itself!