Can't confirm that the password does not show up on 10.0.17. This works as described below.
Any chance that you were executing SHOW GRANTS on a user without password?
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Your MariaDB connection id is 10
Server version: 10.0.17-MariaDB MariaDB Server
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MariaDB [(none)]> show grants for bkp@'localhost'\G
*************************** 1. row ***************************
Grants for bkp@localhost: GRANT RELOAD, LOCK TABLES, REPLICATION CLIENT ON *.* TO 'bkp'@'localhost' IDENTIFIED BY PASSWORD '*77863EC97510887DF16C59D8F7B8E31A0C584C7D'