I've noticed quite a few people recently with a 0% acceptance rate. (and more than I'd seen in the past).
I'm not sure what could be causing this, but I think one thing may help to steer these new users in the right direction is an announcement/update put to them when their acceptance rate is 0%.
By announcement I mean how it will alert you when you get new badges and such. I had something in mind like
You have a 0% acceptance rate. You should learn more about how to accept answers and how the site works
(where bold is relevant links)