The value of a post is nothing, just as the value of everything else in the world. It is you and a community/culture of like minded people that give something value and encourage its value. You can't measure the worth of a post anymore then you can a person and an attempt to do so will never give anyone satisfactory results.

The XP system is a way of saying whether we feel it had merit in the community an if it might at some point assist someone else on their road to Perl enlightenment or possibly be a nice diversion from the norm, or at the very least made you think about things outside your level.

Furthermore the XP system is established to give us a sense of belonging and acceptance among our fellow Perl programmers. This is a much needed part of any community especially in one where its members may never meet face to face.

Your refraining from posting pun/joke/foo/bar replies is simply a natural (intelligent/mature) human response. It is that for two reasons.

1. You don't know if the other people reading it will in fact understand or get your post in the context it was intended, especially since this is a global community. For example the word fag in England vs. fag in America makes a big difference or did at one point anyway.
2. It exposes a side of you that could be perceived as less then professional and could have the adverse effect of people skipping your posts in the future because they assume that you have simply posted another "gag" node that has no real meat.

So I would say you should be happy that you are semi normal, with normal being just as subjective as value :)