nope, not unreasonable at all! I do it for most of my stuff, fannish or not.

for me, its not about credits. I do what I love, and I could give a flying fuck about whether people credits me or not - as long as they're not stealing it and claiming it as theirs. What erks me more is the misuse of my stuff - watermarks can help with that some what, so imho, it's ok :)