Why don't people use their real names on this forum?

Why do some users on these forums (forua?) not use their real names?  There was one 'named' HaHa HoHo and I could provide more examples.  My point is that this is (should be) a professional place where we are all proud of what we do and sometimes have some questions and/or want to learn.  Do these people have something to hide?  Pirated software perhaps?  Don't want their employer finding out where they get the answers to "How do I do this?" or "Why isn't this working?"

...or maybe is is a simple case of their real name is a 'symbol' as in the "artist formerly known as Prince"?

SolidworksGeneral