Fun is Important™. Yet, we at Stack Exchange tend to hate it (edit it out, close it as not useful, etc.), unless it's in "irrelevant" places like chat and the comments section.
As long as it doesn't detract from the question at hand (meaning, the question minus the fun would still be valid) or otherwise impede the site's ability to function, why should we actively (or even passively) punish the programmer's/sysadmin's/whoever's sense of humor?
Some users (like myself) enjoy a small bit of humor in a question to break up the monotony. Dealing with the same boring flags in the VLQ queue is boring.
For the sake of argument, let's define fun as:
- Our Lord and Savior, Jeff Atwood
- [insert pop culture reference]
- Hamsters (although this is a joke question itself, so it's slightly different)
- Anything extra to make things less boring.