But if they see their votes are worth something...

I think that even a tiny something helps. I happened to join right after HF18 when the reward pool algorithm was redone, severely reducing payouts. But as a noob, I had no idea that was what was happening. Four or five posts got zero. Was about to give up but then the reward pool slowly started ramping up and I got a few pennies for a post. Psychologically, it was a huge boost. Like Steve Martin in The Jerk, "I'm somebody!"