For knowledge, I guess.

Agreed. Any TD worth their salt should understand the pairing rules and how to make pairings by hand if necessary. Why? Because the pairing programs sometimes make ridiculous mistakes and it's not good enough to say "the computer makes the pairings."

I have worked with a couple of directors who have said this. It means they shouldn't be behind the computer, and sure as heck shouldn't be on the floor. But hey, they are cheaper!

The Tournament Director is responsible for the pairings. I happen to use Swiss-Sys to make my pairings, but I always take at least a minute to quick-check my pairings for mistakes before posting them. Especially the top few scoregroups, and especially in the late rounds. Experienced players WILL tell you if something is wrong (or could be debated).

FIDE pairing rules are pretty much black-and-white, complete with mathematical formulas and all. With the USCF more than one set of pairings is often possible, and this causes players to voice their concerns (a euphemism for "yell and curse at the TD").

I never thought about "getting something" for my membership dues. I understand that the USCF collects dues in order to keep the organization running. The USCF (and FIDE on the international level) are critical to organized, tournament chess. Without them, there wouldn't be official tournaments, titles, anything.

For casual players, ruling bodies aren't really needed. But for those of us who play in tournaments and play for titles and so on, these bodies are indispensible.