Today there's no version/compatibility information stored in hive metastore. Also the datanucleus configuration property to automatically create missing tables is enabled by default. If you happen to start an older or newer hive or don't run the correct upgrade scripts during migration, the metastore would end up corrupted. The autoCreate schema is not always sufficient to upgrade metastore when migrating to newer release. It's not supported with all databases. Besides the migration often involves altering existing table, changing or moving data etc.
Hence it's very useful to have some consistency check to make sure that hive is using correct metastore and for production systems the schema is not automatically by running hive.