Why are there moderators?

What real purpose do they even serve?

What I've seen moderators do: move posts that they consider to be in the wrong category (in their opinions, no-one else's)

What I've seen general posters do:

1) post useful information for other members (occaisionally moderators seem to manage this information, but not posting useful, specific information more than other members - note that some boards much better than others in this regard (ie Travel Tech = best)

2) self-regulate ignoring inflammatory members with no general, positive contributions.

Do moderators get paid, or is it just the general sense of power that they have that attracts them to spend the hours "policing" their boards for "incorrectly assigned posts".

Retarded, waste of time, and narrow-minded, IMHO