I've only played comp. for maybe 7 years or so, but I've captained for probably five of those, and found it easy, fun and rewarding. I appreciated that it's not USTA, (as in my post above) and probably easier, but captaining is a privilege really. I mean, we're talking about taking time out from our comfortable lives to play sport, and help others to play sport - we're not picking children's bodies from the ruins of war-torn Beirut for goodness' sake. For a couple of years I was also Club Captain at my club, which means I organised about 20 teams, liaised with the captains, helped them fill their teams, made sure the grounds-people prepared the courts, talked to the different associations, did court allocations etc. Again, it was a fair bit of work, but rewarding. My favourite job was opening the club on Saturdays; at 8.00 it was empty, then by 9.00 there were 12 courts with 48 guys playing matches all enjoying themselves. It's nice to be able to do that. After a couple of years I figured I'd done my bit so I stopped.
I'd like to add a bit of balance to the OP's quite long thread about how captaining can be frustrating - my point is that my experience is that Captaining is fun, easy and rewarding. As long as you have demi-decent organisational skills and remember people are people and you'll have to work with that, you'll be fine.