That is a thoughtful question, dabeaner, which I have pondered for lo, at least 10 seconds. I believe that animals of the feline persuasion adore seafood because:
1) it often possesses a very strong odor (and not always good);
2) they do not know that seafood comes from the sea (their owners seldom divulge this fact.)
3) biggest reason - see number 1.
How do I know all this? I possess supernatural skills which I am currently using on supernatural "Interviews." :)