I read that bats are the source of coronavirus, but the virus gets to us via a second animal like a civet or a camel. what is so special about bats?

Bats: Bats are a source of various viruses. In the United States they are most associated with rabies. In the case of coronavirus as I understand it the bats immune system is particularly commensal with the virus.

Genome study.: One study of genome sequences from 5 patients, found that strains of nCoV-2019 were 96% identical to a bat coronavirus. “Genomic characterization and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding,” - Chinese Center for Disease Control and Prevention, Beijing, China.

It's complicated: Bats carry more viruses that can infect humans than any other animal. The bats have a variety of adaptations that allow them to harbor viruses without getting sick themselves. They only allow us 400 characters so there is not enough room to explain here but this article gives a good concise explanation: https://www.iflscience.com/plants-and-animals/why-do-bats-transmit-so-many-diseases/