Lost 22 rating points on a timeout draw?

Granted, I had zero chance of winning, although my opponent certainly had the material to win. He failed to make his move within the allotted time and I got the message that the game times out, but was a draw due to insufficient material? Doesn't sound kosher to me? Why would I lose points on such a draw?

Yes, insufficient material -  you've only got a King left - you've got no mating material. You lose points because he is lower rated.

Shouldn't a draw be zero/zero? Especially since he timed out?

No, it'd be zero'/zero if you were exactly the same rating, but since you are higher and expected to win, your rating drops.

When there is insufficient mating material the game immediately ends.  You cannot overstep the time limit.