I found the solution.
It happens because "atlas_titan" is a zombie hbase table. It can't be created(hbase says table exists) and it can't be dropped(hbase says table does not exist). This happens when table doesn't exist in hbase but exists in zookeeper. It should be deleted from zookeeper.
$ hbase zkcli
[zk: ...] ls /hbase-unsecure/table
[zk: ...] rmr /hbase-unsecure/table/ATLAS_ENTITY_AUDIT_EVENTS
[zk: ...] rmr /hbase-unsecure/table/atlas_titan
[zk: ...] quit
Then restart atlas, it should recreate hbase tables and application should be up a few seconds later.